BNL Home
March 2017
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  1. RIKEN Lunch Seminar

    12:30 pm, Building 510, Room 2-160

    Hosted by: ''Hiromichi Nishimura''

    Symmetry and its spontaneous breaking are of basic importance for understanding the low energy physics in many-body systems. When a continuum symmetry is spontaneously broken, there exist a zero mode called Nambu-Goldstone (NG) mode, which is well developed in Lorentz invariant systems. In contrast, in non-Lorentz invariant systems, the NG theorem has not been well developed. In this talk, we discuss the recent progress in generalization of NG theorem in non-relativistic systems, open systems, and systems with higher form symmetries.

  2. Condensed-Matter Physics & Materials Science Seminar

    1:30 pm, Bldg. 734, ISB Conference Room 201 (upstairs)

    Hosted by: ''''Gabi Kotliar''''

    TBA

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  1. NSLS-II Friday Lunchtime Seminar Series

    12 pm, NSLS-II Bldg 743 (LOB 3), room 156

    Hosted by: ''Ben Ocko and Shirish Chodankar''

  2. HET Lunch Discussions

    12:15 pm, Building 510, Room 2-160

    Hosted by: '''Christoph Lehner'''

    Searches for permanent electric dipole moments (EDM) of neutrons, protons, and nuclei are the most sensitive probes for CP violation, which is necessary for baryogenesis. Currently developed experiments will improve bounds on the neutron EDM by 2-3 orders of magnitude. However, to put constraints on CP-violating interactions, nonperturbative QCD calculations of nucleon structure are necessary. I will present some recent developments in lattice calculations of nucleon EDMs induced by quark-gluon CP-odd interaction

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  1. Nuclear Physics Seminar

    11 am, Small Seminar Room, Bldg. 510

    Hosted by: 'Jin Huang'

    In recent years, there been rapid progresses in our understanding of the long-range ridge in small collision system at RHIC and LHC. I will discuss the nature of collectivity (flow) driving the ridge, as well as the dominating non-collective (or non-flow) background that complicates the extraction of the ridge. I shows that the standard multi-particle cumulant method, often used to defined collectivity in heavy ion collisions, is overwhelmed by non-collective background in pp and low multiplicity pPb collisions. This problem is resolved with an alternative method based on two or more subevents separated in pseudorapidity (η), and therefore offers a robust data-driven definition of collectivity based on the existence of long-range azimuthal correlations between multiple distinct η ranges. With this new cumulant method, we are able to probe reliably the event-by-event fluctuation of collectivity in small collision systems.

  2. NSLS-II Engineering Seminar Series

    2 pm, John Dunn Seminar Room, Bldg. 463

    Hosted by: ''Sushil Sharma and Mary Carlucci-Dayton''

    High-resolution monochromators (HRMs) are key components at nuclear resonant scattering beamlines, and their development at the APS has been ongoing for decades. They are used to resolve the frequency spectrum of isotope-specific atomic dynamics using nuclear resonant vibrational spectroscopy and to reduce the enormous electronic charge scattering that accompanies nuclear excitation using synchrotron radiation. The latter allowing the measurement of hyperfine fields using synchrotron Moessbauer spectroscopy. The narrow line-widths (neV) associated with nuclear resonances also offer an excellent diagnostic tool for the characterization of HRMs, and have greatly facilitated their development. HRMs with ultra-high energy-resolution exposed the need for greater energy-alignment stability and prompted the development of cryo-stabilization. A recent prototype sub-meV-bandwidth monochromator for hard X-rays that implements cryo-stabilization has been built that displays a 100-fold improvement in energy-alignment stability over other designs. This unprecedented level of control allows one to observe the intrinsic factors that limit the energy resolution obtainable with silicon. I will present the principle design aspects of this prototype along with its performance, and discuss what has been learned.

  3. Physics Colloquium

    3:30 pm, Large Seminar Room, Bldg. 510

    Hosted by: ''Robert Pisarski''

    I will present an overview of recent theoretical developments related to the science program at the Relativistic Heavy Ion Collider at Brookhaven National Laboratory and the Large Hadron Collider at CERN. Beginning from heavy ion collisions and the creation of the quark gluon plasma, the most perfect and hottest fluid every created on earth, I will proceed to discuss smaller collision systems, like proton+lead collisions. The experimental data from these show strikingly similar features to heavy ion collisions and I will discuss their possible origins. If the physics in these small systems is also dominated by the fluid dynamic behavior of the created matter, experimental measurements combined with theoretical models give us unprecedented access to the fluctuating shape of the proton.

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  1. Environmental & Climate Sciences Department Seminar

    10 am, Conference Room Bldg 815E

    Hosted by: 'Jian Wang'

    Aerosol science and technology enable continual advances in material synthesis and atmospheric pollutant control. Among these advances, one important frontier is characterizing the initial stages of particle formation by real time measurement of particles below 2 nm in size. Sub 2 nm particles play important roles by acting as seeds for particle growth, ultimately determining the final properties of the generated particles. Tailoring nanoparticle properties requires a thorough understanding and precise control of the particle formation processes, which in turn requires characterizing nanoparticle formation from the initial stages. This work pursued two approaches in investigating incipient particle characterization in systems with aerosol formation and growth: (1) using a high-resolution differential mobility analyzer (DMA) to measure the size distributions of sub 2 nm particles generated from high-temperature aerosol reactors, and (2) analyzing the physical and chemical pathways of aerosol formation during combustion. Part. 1. Particle size distributions reveal important information about particle formation dynamics. DMAs are widely utilized to measure particle size distributions. However, our knowledge of the initial stages of particle formation is incomplete, due to the Brownian broadening effects in conventional DMAs. The first part of this presentation discusses the applicability of high-resolution DMAs in characterizing sub 2 nm particles generated from high-temperature aerosol reactors, including a flame aerosol reactor (FLAR) and a furnace aerosol reactor (FUAR). Comparison against a conventional DMA (Nano DMA, Model 3085, TSI Inc.) demonstrated that the increased sheath flow rates and shortened residence time indeed greatly suppressed the diffusion broadening effect in a high-resolution DMA (half mini type). The incipient particle size distributions were discrete, suggesting the formation of stable clusters that may be intermediate phases betw

  2. Particle Physics Seminar

    11 am, Small Seminar Room, Bldg. 510

    Hosted by: 'Michael Begel'

    Electroweak symmetry breaking is a central pillar of the standard model, and experimentally one of the least understood. Many physics scenarios predict modifications to this mechanism resulting in new particles or interactions. This talk will summarize our knowledge of the electroweak sector with a particular focus on the interactions between W-bosons.

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  1. Condensed-Matter Physics & Materials Science Seminar

    11 am, Bldg. 734, ISB Conference Room 201 (upstairs)

    Hosted by: ''Gabi Kotliar''

    In this seminar I will focus two fundamental aspects of strongly correlated metals: the transport properties and the origin of correlation. Recent advances enables us to study quantitatively various properties of two archetypal correlated oxides, vanadium oxides and ruthenates, using the LDA+DMFT method. Both are strongly correlation, these two materials are quite different in their origins of correlation: V2O3 is proximate to a Mott state while Sr2RuO4 is not. Thus V2O3 is regarded as a prototype Mott system, while recent studies emphasize that Sr2RuO4 belongs to new category termed "Hund's metal" in which Hund's coupling is responsible for the correlations. We carried out a systematical theoretical study on the transport properties of V2O3 and ruthenates family. Our computed resistivity and optical conductivity are in very good agreement with experimental measurements, which clearly demonstrates that the strong correlation dominates the transport of this material , despite their origin of correlation. We demonstrated that "resilient quasiparticles" dominates the transport. Furthermore by expressing the resistivity in terms of an effective plasma frequency and an effective scattering rate, we uncover the so-called "hidden Fermi liquid" behavior. We identified signatures of Mottness and Hundness by a comparative study of V2O3 and Sr2RuO4. In V2O3 the low temperature coherent resonance emerges from the pseudogap regime appearing at high temperature between incoherent peaks, while in Sr2RuO4, it emerges from a single incoherent peak with large finite value at the Fermi level.. We show that these two contrasting scenarios features interesting behaviors in the local properties of correlated atoms including charge fluctuations, spin and orbit susceptibility and entropy. The findings shed new lights on the understanding of strongly correlated metals.

  2. RIKEN Lunch Seminar

    12:30 pm, Building 510, Room 1-224

    Hosted by: '''Heikki Mantysaari'''

    Since decades expressions for the thermodynamic potential were calculated perturbatively at finite temperature (and density) and pushed to higher orders. I review the current status of these efforts including resummation techniques and compare them to results of lattice Monte Carlo simulations and address unanswered questions. Finally, I present results for several thermodynamic quantities within the next-to-leading order calculation of the thermodynamic potential at finite T and \mu including non-vanishing quark masses.

  3. Particle Physics Seminar

    3 pm, Small Seminar Room, Bldg. 510

    Hosted by: 'Michael Begel'

    We will review recent diboson measurements and searches in the WW final state performed with the CMS detector. We will discuss the perspectives for some of these measurements with the full HL-LHC dataset. We will briefly describe some of the upgrades being designed for the CMS Silicon Tracker in order to operate in the high pileup environment of the HL-LHC while maintaining excellent performance for the final states discussed in this talk.

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  1. HET Lunch Discussions

    12:15 pm, Building 510, Room 1-224

    Hosted by: 'Christoph Lehner'

  2. Nuclear Theory Seminar

    2 pm, Small Seminar Room, Bldg. 510

    Hosted by: 'Heikki Mantysaari'

    The Skyrme model is a candidate to describe the low energy regime of QCD where baryons and nuclei are topological excitations in a low-energy effective field theory of pions. The Skyrme model and its BPS variant (Skyrme model with a lower topological energy bound which is saturated) have been applied to the description of nuclei with notable recent success, e.g. quantitative description of Carbon-12 (including the Holye state and its rotational band) and of the low-lying energy spectrum of Oxygen-16. In this talk, we test Skyrme theories as models for nuclear matter at high densities and explore the thermodynamical properties of skyrmionic matter at zero temperature. We compute analytically the mean-field equation of state in the high and medium pressure regimes by applying topological bounds on compact domains. We identify which term in a generalised Skyrme model is responsible for which part in the equation of state and compare our findings with the corresponding results in the Walecka model. We find that the BPS submodel plays the dominant role at large densities. The BPS Skyrme model even allows us to derive thermodynamical variables and densities directly from the theory without having to perform a mean-field limit. This distinguishes the BPS Skyrme model from other models of nuclear matter where usually a mean-field limit has to be performed. Note that this is the first of two talks on Skyrme models and their predictions for nuclear matter at high densities. The second part on the description of neutron stars as Skyrme solitons will be given by Carlos Naya (Durham) on March, 24th at BNL.

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  1. HET/RIKEN Seminar

    2 pm, Small Seminar Room, Bldg. 510

    Hosted by: ''Pier Paolo Giardino''

  2. Nuclear Physics Seminar

    3:30 pm, Small Seminar Room, Bldg. 510

    Hosted by: ''Jin Huang''

    sPHENIX, scheduled to start taking data in 2022 at RHIC, is a detector designed to probe the inner workings of the quark gluon plasma by measuring jets and their substructure, heavy flavor tagged jets and quarkonia. The design includes tracking systems, a solenoid magnet and calorimeter system. The calorimeter system, designed to measure the energy of jets, is comprised of an electromagnetic calorimeter, an inner hadronic calorimeter and and outer hadronic calorimeter. Prototypes of these detectors were built and tested in 2016. The results of the test beam show that the performance is well within the requirements set by the sPHENIX program. In addition, the results validate the GEANT4 simulation studies. The design of the sPHENIX calorimeter system, the test beam results from the calorimeter prototypes and additional studies will be presented

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  1. Particle Physics Seminar

    11 am, Small Seminar Room, Bldg. 510

    Hosted by: ''Michael Begel''

    Search for physics beyond the Standard Model (SM) has been one of the most important goals of the physics program at the Large Hadron Collider (LHC).Among all the final states, the multijet final state has long been considered as a challenging one for the search of physics beyond the SM due to its large background. Though, exciting new physics phenomena, such as the production of black hole as well as massive supersymmetric (SUSY) particles, may well result in signals in multijet final state. I present searches for physics beyond the SM using multijet events from 13 TeV collision data taken in 2015 and the first half of 2016 by the ATLAS experiment at the LHC. I focus on a search for the production of black hole and a search for massive supersymmetric particles decaying to many jets via R-Parity Violating (RPV) couplings. The two examples represent searches targeting physics beyond the SM at different mass scales, and therefore different analysis strategies are employed. These searches have greatly improved the sensitivity of the LHC to the black hole production and RPV SUSY scenarios, and they are complementary to searches using events of leptons, photons and missing transverse energy.

  2. RIKEN Lunch Seminar

    12:30 pm, Building 510, Room 2-160

    Hosted by: 'Hiromichi Nishimura'

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  1. HET Lunch Discussions

    12:15 pm, Building 510, Room 2-160

    Hosted by: 'Christoph Lehner'

  2. Nuclear Theory/RIKEN Seminar

    2 pm, Small Seminar Room, Bldg. 510

    Hosted by: 'Heikki Mantysaari'

    Fragmentation is the earliest and perhaps most interesting QCD jet observable, since it directly deals with the parton-hadron duality at the end of the QCD cascade. The most basic fragmentation observables all enjoy the property of being universal, in the sense that a sufficiently energetic parton that initiates the cascade factorizes from the rest of the event, so that the underlying soft structure of the event to a good approximation does not change the fragmentation spectrum. With the luminosities and resolution of modern detectors, we can begin to study the fragmentation process in three dimensions: both the energy spectrum and the transverse fluctuations to the collinear direction of initiating hard parton. However, when one wants to study the transverse fluctuations, one becomes very sensitive to the underlying jet definition, in particular, how the collinear direction is defined. Intuitive definitions of the jet direction, like the total momentum of the jet constituents, are inherently sensitive to soft processes, and can spoil the universality of the spectrum. I will discuss how a simple change in the jet definition removes this soft sensitivity, and allows one to study the intrinsic three dimensional structure of collinear splittings, which should be process independent.

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  1. Particle Physics Seminar

    11 am, Small Seminar Room, Bldg. 510

    Hosted by: ''Michael Begel''

    The large amount of high-energy proton-proton collision data at the LHC provides an unprecedented opportunity to search for new physics beyond the Standard Model at the TeV scale. The 2012 discovery of a 125 GeV Higgs boson opened a new door to understanding the universe, providing an exciting new tool to use in these searches, given it is now produced about once per second at the current collision rate. The talk will review recent ATLAS searches for physics beyond the Standard Model, focusing on the central role of processes with heavy bosons, including the Higgs, and the corresponding new possible signatures that range from spectacular new resonances to subtle changes in kinematic distributions.

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  1. Condensed-Matter Physics & Materials Science Seminar

    11 am, Bldg. 734, ISB Conference Room 201 (upstairs)

    Hosted by: ''Weiguo Yin''

    The nematic phases in iron pnictides are in close proximity to the stripe antiferromagnetic order, suggesting that magnetism is the driving force for the spontaneous 4-fold crystal rotation symmetry breaking. In contrast, bulk FeSe shows a nematic phase below 90K at ambient pressure, but has no magnetic long range order down to very low temperature. This prompts suggestions that the nematicity in FeSe is driven by some other mechanism. We argue that magnetic correlation can still drive nematic order in the absence of magnetic long-range order. By field theoretical considerations and exact diagonalization results on finite size lattices, we conclude that the paramagnetic phase in frustrated spin-1 J_1-J_2 model on square lattice is likely a "nematic quantum paramagnet", which breaks only the crystal 4-fold rotation symmetry. The prototype wavefunctions of such quantum ground states are horizontal(vertical) aligned spin-1 AKLT chains. We suggest that the local spins in FeSe may form this phase due to strong frustration. One unique consequence of this proposal is that the nematic paramagnetic phase will be close to both stripe and Neel antiferromagnetic order, and will thus host low but finite energy spin fluctuations at both ordering wavevectors. Reference: Fa Wang, S. A. Kivelson, and Dung-Hai Lee, Nat. Phys. 11, 959 (2015)

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    Today

    Particle Physics Seminar

    10 am, Small Seminar Room, Bldg. 510

    Friday, March 24, 2017, 10:00 am

    Hosted by: ''Xin Qian''

    The extraction of neutrino mixing parameters and the CP-violating phase requires knowledge of the neutrino energy. This energy must be reconstructed from the final state of a neutrino-nucleus reaction since all long-baseline experiments use nuclear targets. This reconstruction requires detailed knowledge of the neutrino reactions with bound nucleons and of the final state interactions of hadrons with the nuclear environment. Quantum-kinetic transport theory can be used to build an event generator for this reconstruction that takes basic nuclear properties, such as binding, into account. Some examples are discussed that show the effects of nuclear interactions on observables in long-baseline experiments.

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    Today

    HET Lunch Discussions

    12:15 pm, Building 510, Room 2-160

    Friday, March 24, 2017, 12:15 pm

    Hosted by: 'Christoph Lehner'

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    Today

    Condensed-Matter Physics & Materials Science Seminar

    1:30 pm, Bldg. 734, ISB Conference Room 201 (upstairs)

    Friday, March 24, 2017, 1:30 pm

    Hosted by: '''Igor Zaliznyak'''

    TBD

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    Today

    Nuclear Theory/RIKEN Seminar

    2 pm, Small Seminar Room, Bldg. 510

    Friday, March 24, 2017, 2:00 pm

    Hosted by: 'Heikki Mantysaari'

    The Skyrme model is a low energy effective field theory of strong interactions where nuclei and baryons appear as collective excitations of pionic degrees of freedom. Proposed by Tony Skyrme in the sixties, his ideas received further support when it was discovered that in the limit of the large number of colours of QCD, an effective theory of mesons arises. In the last years, there has been a revival of Skyrme's ideas and new related models, some of them with BPS bounds (topological lower energy bounds), have been proposed. It is the aim of this talk to focus on the one known as BPS Skyrme model. After a brief introduction to this BPS limit we study its application to neutron stars where we will find that high maximal masses are supported. In addition, the BPS Skyrme model allow us to perform both mean-field and exact calculations and a comparison between both approaches will be presented.

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    Monday

    Condensed-Matter Physics & Materials Science Seminar

    10 am, ISB Bldg. 734, Conf. Rm. 201 (upstairs)

    Monday, March 27, 2017, 10:00 am

    Hosted by: 'Mark Dean'

    I will describe Resonant Inelastic X-Ray Scattering (RIXS) experiments performed at the Swiss Light Source focusing on the detection of high-energy spin fluctuations on iron pnictides. I will show that RIXS has been successfully used to extract the spin excitation spectrum on NaFeAs, BaFe2As2, EuFe2As2 and SmFeAsO, parent compounds [1-3]. We investigated electron-doped NaFe1-xCoxAs observing the persistence of broad dispersive magnetic excitations in optimal and overdoped samples [1]. The energy of such modes is unaffected by doping and the magnetic weight per iron atom of magnons / paramagnons remains constant, demonstrating the impurity role of Co doping. The persistence of magnetic spectral weight is also caught by theoretical calculations. In the second part of the talk, I will present a combined Fe-L3 RIXS and Fe-Kβ X-rays emission spectroscopy (XES) study of isovalently doped BaFe2(As1-xPx)2 spanning a large portion of the phase diagram. RIXS measurements find the persistence of broad dispersive magnetic excitations for all doping levels. Remarkably, the energy of such modes is strongly hardened by doping differently from the cases of electron- and hole-doped BaFe2As2 [5]. On the other hand, XES experiments show a gradual quenching of the local magnetic moment, which is intriguing if compared to the behavior of spin correlations. We link the unconventional evolution of magnetism to the shift from 2- to 3-dimensional electronic structure of the system, hand in hand with the warping of the Fermi surface. Combined together these findings help to shed light on the real degree of electronic correlations in Fe pnictides. References [1] J. Pelliciari et al., Phys. Rev. B, 93, 134515 (2016); [2] J. Pelliciari et al., Appl. Phys. Lett. 109, 122601 (2016); [3] J. Pelliciari et al., "Local and collective magnetism of EuFe2As2" accepted in Phys. Rev. B (2017); [4] K. J. Zhou et al, Nat. Comm., 4, 1470 (2013)

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    Tuesday

    Nuclear Physics Seminar

    11 am, Small Seminar Room, Bldg. 510

    Tuesday, March 28, 2017, 11:00 am

    Hosted by: 'Jin Huang'

    Recent STAR measurements of azimuthal anisotropy have focused on the use of two- and multi-particle correlations as probes for model constraints for the temperature dependence of the specific shear viscosity $\eta/s$ and the initial-state structure of the collision zone. We will discuss and summarize recent two- and multi-particle correlations measurements of $v_n$ $(n > 1)$ , dipolar flow $v^{even}_1$, and $\langle cos(n \varphi_{1} + m \varphi_{2} - (n+m) \varphi_{3}) \rangle$, as a function of centrality, transverse momentum ($p_T$), and pseudorapidity ($\eta$) for $Au+Au$ at ($\sqrt{s_{NN}} = 7 - 200$~GeV;{em BES-I}), $U+U$ at ($\sqrt{s_{NN}} = 193$ GeV) and $Cu+Au$ , $Cu+Cu$ ,$d+Au$ ,$p+Au$ at ($\sqrt{s_{NN}} = 200$ GeV).

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    Tuesday

    Condensed-Matter Physics & Materials Science Seminar

    1:30 pm, Bldg. 734, ISB Conference Room 201 (upstairs)

    Tuesday, March 28, 2017, 1:30 pm

    Hosted by: ''Neil Robinson''

    We employ equation of motion techniques to study the non-equilibrium dynamics in a lattice model of weakly interacting spinless fermions. Our model provides a simple setting for analyzing the effects of weak integrability breaking perturbations on the time evolution after a quantum quench. We establish the accuracy of the method by comparing results at short and intermediate times to time-dependent density matrix renormalization group computations. For sufficiently weak integrability-breaking interactions we always observe prethermalization plateaux, where local observables relax to non-thermal values at intermediate time scales. At later times a crossover towards thermal behaviour sets in. We determine the associated time scale, which depends on the initial state, the band structure of the non-interacting theory, and the strength of the integrability breaking perturbation. Our method allows us to analyze in some detail the spreading of correlations and in particular the structure of the associated light cones in our model. We find that the interior and exterior of the light cone are separated by an intermediate region, the temporal width of which appears to scale with a universal power-law t 1/3.

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    Tuesday

    Physics Colloquium

    3:30 pm, Large Seminar Room, Bldg. 510

    Tuesday, March 28, 2017, 3:30 pm

    Hosted by: ''Robert Pisarski''

    The theory of complex variables is extremely useful because it helps to explain the mathematical behavior of functions of a real variable. Complex variable theory also provides insight into the nature of physical theories. For example, it provides a simple and beautiful picture of quantization and it explains the underlying reason for the divergence of perturbation theory. By using complex-variable methods one can generalize conventional Hermitian quantum theories into the complex domain. The result is a new class of parity-time-symmetric (PT-symmetric) theories whose remarkable physical properties have been studied and verified in many recent laboratory experiments.

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    Thursday

    Particle Physics Seminar

    11 am, Small Seminar Room, Bldg. 510

    Thursday, March 30, 2017, 11:00 am

    Hosted by: ''Xin Qian''

    The 'standard' model of cosmology is founded on the basis that the expansion rate of the universe is accelerating at present – as was inferred from the Hubble disgram of Type la supernovae. There exists now a much bigger database of supernovae so we can perform rigorous statistical tests to check whether these 'standardisable candles' indeed indicate cosmic acceleration. Taking account of the empirical procedure by which corrections are made to their absolute magnitudes to allow for the varying shape of the light curve and extinction by dust, we find that the data are still consistent with a constant rate of expansion. The implications of this will be discussed.

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    Thursday

    Condensed-Matter Physics & Materials Science Seminar

    1:30 pm, ISB Bldg. 734, Conf. Rm. 201 (upstairs)

    Thursday, March 30, 2017, 1:30 pm

    Hosted by: 'Cedomir Petrovic'

    In strongly correlated electron materials, the delicate interplay between spin, charge, and lattice degrees of freedom often leads to extremely rich phase diagrams exhibiting intrinsic phase inhomogeneities. The key to understanding such complexities usually lies in the characterization and control of these materials at fundamental energy, time and length scales. I will use this opportunity to report the recent advances in the IR and THz near-field microscopy and spectroscopy, and explain how they can be used to probe electronic/structural phase transitions with unprecedented spatial and temporal resolutions. Specifically, with scanning near-field infrared microscopy we resolved the insulator to metal phase transitions in 3d (VO2), 4d (Ca2RuO4) and 4f (SmS) materials with ~10 nm resolution over a broad spectral range. The results set the stage for future spectroscopic investigations to access the fundamental properties of complex materials.

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    Thursday

    Particle Physics Seminar

    3 pm, Small Seminar Room, Bldg. 510

    Thursday, March 30, 2017, 3:00 pm

    Hosted by: 'Xin Qian'

    Evaluation of the reactor antineutrino flux and spectrum is an essential ingredient of their application in the neutrino oscillation studies. Two anomalies, i.e. discrepancies between the observed and expected count rates, are widely discussed at the present time. The total rate is about 6% lower than the expectation at all distances > 10 m from the reactor. And there is a shoulder (often referred to as "bump") at neutrino energies 5-7 MeV, not predicted in the calculated spectrum. I review the ways the flux and spectrum is evaluated. I argue that far reaching conclusions based on these anomalies should await a thorough understanding of the uncertainties of the spectrum, and point out possible standard physics sources of the anomalies.

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    Thursday

    Provost Lecture

    4 pm, Simons Center Della Pietra Family Auditorium, Room

    Thursday, March 30, 2017, 4:00 pm

    Hosted by: 'Jon Longtin, SBU'

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    Friday

    Particle Physics Seminar

    11 am, Small Seminar Room, Bldg. 510

    Friday, March 31, 2017, 11:00 am

    Hosted by: '''Xin Qian'''

    Search for the neutrinoless double beta decay is one of the main goals of nuclear physics community worldwide. If observed, it would be an example of "physics beyond the Standard Model", showing that the lepton number is not a conserved quantity and that neutrinos are massive Majorana fermions. After introducing the subject and its particle physics consequences I will concentrate on the issue of evaluation of the nuclear matrix elements. Despite decades of effort and hundreds of publications, different approaches give results that differ by roughly a factor of three, and it is difficult to decide which of them is the most realistic. I will describe the strengths and weaknesses of the nuclear models used. In addition, I will discuss the problem of "quenching", i.e. of reduction of the matrix elements of weak axial current in complex nuclei, that potentially affects the neutrinoless double beta decay matrix element values signiffcantly

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    Friday

    Instrumentation Division Seminar

    2:30 pm, Large Conference Room, Bldg. 535

    Friday, March 31, 2017, 2:30 pm

    We are now in the era of ultrafast imaging, which is the ability to observe transient events with a time duration no longer than 100 ps (one billionth of the time for eye blinking). Innovative methods have demonstrated photography at the mind-bending speed of one trillion frames per second. Several recent advances make ultrafast imaging possible: ultrashort lasers and X-rays for illumination, abilities to harvest ultrafast responses in materials for efficient photon and electron detection, innovative ways to store and process data. It will be shown that ultrafast imaging technology is a natural fit to mesoscopic science. Meanwhile, ultrafast imaging technology also permits photography of macroscopic objects around the corner or hidden away from the direct line of sight. One recent LANL interest in ultrafast high-energy X-ray imaging is driven by MaRIE. Some material challenges will be highlighted towards a GHz frame-rate burst mode camera for photons at above 30 keV energies.

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    Today

    Particle Physics Seminar

    "Neutrino Interactions with Nuclei and Long-Baseline Experiments"

    Presented by Professor Ulrich Mosel, Giessen University

    10 am, Small Seminar Room, Bldg. 510

    Friday, March 24, 2017, 10:00 am

    Hosted by: ''Xin Qian''

    The extraction of neutrino mixing parameters and the CP-violating phase requires knowledge of the neutrino energy. This energy must be reconstructed from the final state of a neutrino-nucleus reaction since all long-baseline experiments use nuclear targets. This reconstruction requires detailed knowledge of the neutrino reactions with bound nucleons and of the final state interactions of hadrons with the nuclear environment. Quantum-kinetic transport theory can be used to build an event generator for this reconstruction that takes basic nuclear properties, such as binding, into account. Some examples are discussed that show the effects of nuclear interactions on observables in long-baseline experiments.

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    Today

    HET Lunch Discussions

    "Baryogenesis and Dark Matter in the exo-Higgs scenario"

    Presented by Pier Paolo Giardino, BNL

    12:15 pm, Building 510, Room 2-160

    Friday, March 24, 2017, 12:15 pm

    Hosted by: 'Christoph Lehner'

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    Today

    Condensed-Matter Physics & Materials Science Seminar

    "Shining a light on high-Tc superconductivity"

    Presented by Peter Johnson, BNL

    1:30 pm, Bldg. 734, ISB Conference Room 201 (upstairs)

    Friday, March 24, 2017, 1:30 pm

    Hosted by: '''Igor Zaliznyak'''

    TBD

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    Today

    Nuclear Theory/RIKEN Seminar

    "A solitonic approach to neutron stars: The (BPS) Skyrme model"

    Presented by Carlos Naya, Durham

    2 pm, Small Seminar Room, Bldg. 510

    Friday, March 24, 2017, 2:00 pm

    Hosted by: 'Heikki Mantysaari'

    The Skyrme model is a low energy effective field theory of strong interactions where nuclei and baryons appear as collective excitations of pionic degrees of freedom. Proposed by Tony Skyrme in the sixties, his ideas received further support when it was discovered that in the limit of the large number of colours of QCD, an effective theory of mesons arises. In the last years, there has been a revival of Skyrme's ideas and new related models, some of them with BPS bounds (topological lower energy bounds), have been proposed. It is the aim of this talk to focus on the one known as BPS Skyrme model. After a brief introduction to this BPS limit we study its application to neutron stars where we will find that high maximal masses are supported. In addition, the BPS Skyrme model allow us to perform both mean-field and exact calculations and a comparison between both approaches will be presented.

  5. MAR

    27

    Monday

    Condensed-Matter Physics & Materials Science Seminar

    "Resonant Inelastic X-ray Scattering and X-ray Emission Spectroscopy of Iron Pnictide Superconductors"

    Presented by Jonathan Pelliciari, Paul Scherrer Institute, Switzerland

    10 am, ISB Bldg. 734, Conf. Rm. 201 (upstairs)

    Monday, March 27, 2017, 10:00 am

    Hosted by: 'Mark Dean'

    I will describe Resonant Inelastic X-Ray Scattering (RIXS) experiments performed at the Swiss Light Source focusing on the detection of high-energy spin fluctuations on iron pnictides. I will show that RIXS has been successfully used to extract the spin excitation spectrum on NaFeAs, BaFe2As2, EuFe2As2 and SmFeAsO, parent compounds [1-3]. We investigated electron-doped NaFe1-xCoxAs observing the persistence of broad dispersive magnetic excitations in optimal and overdoped samples [1]. The energy of such modes is unaffected by doping and the magnetic weight per iron atom of magnons / paramagnons remains constant, demonstrating the impurity role of Co doping. The persistence of magnetic spectral weight is also caught by theoretical calculations. In the second part of the talk, I will present a combined Fe-L3 RIXS and Fe-Kβ X-rays emission spectroscopy (XES) study of isovalently doped BaFe2(As1-xPx)2 spanning a large portion of the phase diagram. RIXS measurements find the persistence of broad dispersive magnetic excitations for all doping levels. Remarkably, the energy of such modes is strongly hardened by doping differently from the cases of electron- and hole-doped BaFe2As2 [5]. On the other hand, XES experiments show a gradual quenching of the local magnetic moment, which is intriguing if compared to the behavior of spin correlations. We link the unconventional evolution of magnetism to the shift from 2- to 3-dimensional electronic structure of the system, hand in hand with the warping of the Fermi surface. Combined together these findings help to shed light on the real degree of electronic correlations in Fe pnictides. References [1] J. Pelliciari et al., Phys. Rev. B, 93, 134515 (2016); [2] J. Pelliciari et al., Appl. Phys. Lett. 109, 122601 (2016); [3] J. Pelliciari et al., "Local and collective magnetism of EuFe2As2" accepted in Phys. Rev. B (2017); [4] K. J. Zhou et al, Nat. Comm., 4, 1470 (2013)

  6. MAR

    28

    Tuesday

    Nuclear Physics Seminar

    "Beam energy and system dependence of anisotropic flow measurements from STAR"

    Presented by Niseem Magdy, Stony Brook University

    11 am, Small Seminar Room, Bldg. 510

    Tuesday, March 28, 2017, 11:00 am

    Hosted by: 'Jin Huang'

    Recent STAR measurements of azimuthal anisotropy have focused on the use of two- and multi-particle correlations as probes for model constraints for the temperature dependence of the specific shear viscosity $\eta/s$ and the initial-state structure of the collision zone. We will discuss and summarize recent two- and multi-particle correlations measurements of $v_n$ $(n > 1)$ , dipolar flow $v^{even}_1$, and $\langle cos(n \varphi_{1} + m \varphi_{2} - (n+m) \varphi_{3}) \rangle$, as a function of centrality, transverse momentum ($p_T$), and pseudorapidity ($\eta$) for $Au+Au$ at ($\sqrt{s_{NN}} = 7 - 200$~GeV;{em BES-I}), $U+U$ at ($\sqrt{s_{NN}} = 193$ GeV) and $Cu+Au$ , $Cu+Cu$ ,$d+Au$ ,$p+Au$ at ($\sqrt{s_{NN}} = 200$ GeV).

  7. MAR

    28

    Tuesday

    Condensed-Matter Physics & Materials Science Seminar

    "Thermalization and light cones in a model with weak integrability breaking"

    Presented by Stefan Groha, University of Oxford, United Kingdom

    1:30 pm, Bldg. 734, ISB Conference Room 201 (upstairs)

    Tuesday, March 28, 2017, 1:30 pm

    Hosted by: ''Neil Robinson''

    We employ equation of motion techniques to study the non-equilibrium dynamics in a lattice model of weakly interacting spinless fermions. Our model provides a simple setting for analyzing the effects of weak integrability breaking perturbations on the time evolution after a quantum quench. We establish the accuracy of the method by comparing results at short and intermediate times to time-dependent density matrix renormalization group computations. For sufficiently weak integrability-breaking interactions we always observe prethermalization plateaux, where local observables relax to non-thermal values at intermediate time scales. At later times a crossover towards thermal behaviour sets in. We determine the associated time scale, which depends on the initial state, the band structure of the non-interacting theory, and the strength of the integrability breaking perturbation. Our method allows us to analyze in some detail the spreading of correlations and in particular the structure of the associated light cones in our model. We find that the interior and exterior of the light cone are separated by an intermediate region, the temporal width of which appears to scale with a universal power-law t 1/3.

  8. MAR

    28

    Tuesday

    Physics Colloquium

    "Physics in the complex domain"

    Presented by Carl Bender, Washington University

    3:30 pm, Large Seminar Room, Bldg. 510

    Tuesday, March 28, 2017, 3:30 pm

    Hosted by: ''Robert Pisarski''

    The theory of complex variables is extremely useful because it helps to explain the mathematical behavior of functions of a real variable. Complex variable theory also provides insight into the nature of physical theories. For example, it provides a simple and beautiful picture of quantization and it explains the underlying reason for the divergence of perturbation theory. By using complex-variable methods one can generalize conventional Hermitian quantum theories into the complex domain. The result is a new class of parity-time-symmetric (PT-symmetric) theories whose remarkable physical properties have been studied and verified in many recent laboratory experiments.

  9. MAR

    30

    Thursday

    Particle Physics Seminar

    "Is there evidence for cosmic acceleration?"

    Presented by Subir Sarkar, Oxford University

    11 am, Small Seminar Room, Bldg. 510

    Thursday, March 30, 2017, 11:00 am

    Hosted by: ''Xin Qian''

    The 'standard' model of cosmology is founded on the basis that the expansion rate of the universe is accelerating at present – as was inferred from the Hubble disgram of Type la supernovae. There exists now a much bigger database of supernovae so we can perform rigorous statistical tests to check whether these 'standardisable candles' indeed indicate cosmic acceleration. Taking account of the empirical procedure by which corrections are made to their absolute magnitudes to allow for the varying shape of the light curve and extinction by dust, we find that the data are still consistent with a constant rate of expansion. The implications of this will be discussed.

  10. MAR

    30

    Thursday

    Condensed-Matter Physics & Materials Science Seminar

    "Explore Mesoscopic Physics in Strongly Correlated Electron Materials with IR near-field microscopy and spectroscopy"

    Presented by Mengkun Liu, Stony Brook University

    1:30 pm, ISB Bldg. 734, Conf. Rm. 201 (upstairs)

    Thursday, March 30, 2017, 1:30 pm

    Hosted by: 'Cedomir Petrovic'

    In strongly correlated electron materials, the delicate interplay between spin, charge, and lattice degrees of freedom often leads to extremely rich phase diagrams exhibiting intrinsic phase inhomogeneities. The key to understanding such complexities usually lies in the characterization and control of these materials at fundamental energy, time and length scales. I will use this opportunity to report the recent advances in the IR and THz near-field microscopy and spectroscopy, and explain how they can be used to probe electronic/structural phase transitions with unprecedented spatial and temporal resolutions. Specifically, with scanning near-field infrared microscopy we resolved the insulator to metal phase transitions in 3d (VO2), 4d (Ca2RuO4) and 4f (SmS) materials with ~10 nm resolution over a broad spectral range. The results set the stage for future spectroscopic investigations to access the fundamental properties of complex materials.

  11. MAR

    30

    Thursday

    Particle Physics Seminar

    "Evaluation of reactor neutrino flux: issues and uncertainties"

    Presented by Professor Petr Vogel, Caltech

    3 pm, Small Seminar Room, Bldg. 510

    Thursday, March 30, 2017, 3:00 pm

    Hosted by: 'Xin Qian'

    Evaluation of the reactor antineutrino flux and spectrum is an essential ingredient of their application in the neutrino oscillation studies. Two anomalies, i.e. discrepancies between the observed and expected count rates, are widely discussed at the present time. The total rate is about 6% lower than the expectation at all distances > 10 m from the reactor. And there is a shoulder (often referred to as "bump") at neutrino energies 5-7 MeV, not predicted in the calculated spectrum. I review the ways the flux and spectrum is evaluated. I argue that far reaching conclusions based on these anomalies should await a thorough understanding of the uncertainties of the spectrum, and point out possible standard physics sources of the anomalies.

  12. MAR

    30

    Thursday

    Provost Lecture

    "Life and Evolution as Physics"

    Presented by Adrian Bejan, Duke University

    4 pm, Simons Center Della Pietra Family Auditorium, Room

    Thursday, March 30, 2017, 4:00 pm

    Hosted by: 'Jon Longtin, SBU'

  13. MAR

    31

    Friday

    Particle Physics Seminar

    "neutrinoless double beta decay and nuclear structure theory"

    Presented by Professor Petr Vogel, Caltech

    11 am, Small Seminar Room, Bldg. 510

    Friday, March 31, 2017, 11:00 am

    Hosted by: '''Xin Qian'''

    Search for the neutrinoless double beta decay is one of the main goals of nuclear physics community worldwide. If observed, it would be an example of "physics beyond the Standard Model", showing that the lepton number is not a conserved quantity and that neutrinos are massive Majorana fermions. After introducing the subject and its particle physics consequences I will concentrate on the issue of evaluation of the nuclear matrix elements. Despite decades of effort and hundreds of publications, different approaches give results that differ by roughly a factor of three, and it is difficult to decide which of them is the most realistic. I will describe the strengths and weaknesses of the nuclear models used. In addition, I will discuss the problem of "quenching", i.e. of reduction of the matrix elements of weak axial current in complex nuclei, that potentially affects the neutrinoless double beta decay matrix element values signiffcantly

  14. MAR

    31

    Friday

    Instrumentation Division Seminar

    "Ultrafast imaging technology: from visible light to high-energy X-ray photons"

    Presented by Zhehui Wang, LANL

    2:30 pm, Large Conference Room, Bldg. 535

    Friday, March 31, 2017, 2:30 pm

    We are now in the era of ultrafast imaging, which is the ability to observe transient events with a time duration no longer than 100 ps (one billionth of the time for eye blinking). Innovative methods have demonstrated photography at the mind-bending speed of one trillion frames per second. Several recent advances make ultrafast imaging possible: ultrashort lasers and X-rays for illumination, abilities to harvest ultrafast responses in materials for efficient photon and electron detection, innovative ways to store and process data. It will be shown that ultrafast imaging technology is a natural fit to mesoscopic science. Meanwhile, ultrafast imaging technology also permits photography of macroscopic objects around the corner or hidden away from the direct line of sight. One recent LANL interest in ultrafast high-energy X-ray imaging is driven by MaRIE. Some material challenges will be highlighted towards a GHz frame-rate burst mode camera for photons at above 30 keV energies.

  15. APR

    4

    Tuesday

    Nuclear Physics Seminar

    "New insights to the search for the anomalous chiral effects using small colliding system at the LHC"

    Presented by Zhoudunming Tu, Rice University

    11 am, Small Seminar Room, Bldg. 510

    Tuesday, April 4, 2017, 11:00 am

    Hosted by: 'Jiangyong Jia'

    In relativistic heavy ion collisions, anomalous chiral effects have been predicted to occur in presence of a strong magnetic field induced by the spectator protons, e.g., the chiral magnetic effect (CME) and chiral magnetic wave (CMW). In the past decade, measurements of CME and CMW have been attempted from RHIC to the LHC energies, where significant signals were found to be in line with expectations of the chiral effects. However, soon after the initial excitement, various sources of background effects were identified and proposed to qualitatively describe the data. The origin of the backgrounds has been extensively studied, but still remains inconclusive to date. Recently, novel collective phenomenon has been found in high-multiplicity pA collisions, similar to those in AA collisions. Due to the weak correlation between the magnetic field direction and the event plane, the high-multiplicity pPb data are expected to have much suppressed CME and CMW signal, comparing to that in PbPb collisions, and thus provide an ideal testing ground to observables related to the anomalous chiral effects. In this talk, I will present new measurements related to the CME and CMW from CMS in pPb and PbPb collisions at the LHC, and discuss their implications to the search for the anomalous chiral effects including an outlook for future studies.

  16. APR

    5

    Wednesday

    HET Seminar

    "Hints of New Physics in Semi-leptonic B-meson Decays"

    Presented by Diptimoy Ghosh, Weizman

    2 pm, Small Seminar Room, Bldg. 510

    Wednesday, April 5, 2017, 2:00 pm

    Hosted by: ''Amarjit Soni''

    In recent years, a number of interesting signals of potential new physics in semi-leptonic B-meson decays have been reported both by the B-factories as well as the LHCb. In this talk, I will discuss these observations with a particular emphasis on the observable $R_{D^*}$, the ratio of the branching fraction of $\bar{B} \to D^* \tau \bar{\nu}_\tau$ to that of $\bar{B} \to D^* \ell \bar{\nu}_\ell (\ell = \mu, e )$, which shows a 3.3 sigma deviation from the Standard Model prediction. I will present an effective field theory analysis of these potential new physics signals and discuss possible ways to distinguish the various operators.

  17. APR

    7

    Friday

    Nuclear Theory/RIKEN Seminar

    "TBA"

    Presented by Dirk Rischke, Johann Wolfgang Goethe-Universitat

    2 pm, Small Seminar Room, Bldg. 510

    Friday, April 7, 2017, 2:00 pm

    Hosted by: 'Heikki Mantysaari'

  18. APR

    13

    Thursday

    Particle Physics Seminar

    "Natural Seesaw in Warped/Composite Higgs framework and its LHC Signals"

    Presented by Kaustubh Agashe, University of Maryland

    3 pm, Small Seminar Room, Bldg. 510

    Thursday, April 13, 2017, 3:00 pm

    Hosted by: ''Christoph Lehner''

    I will show how a natural seesaw model for SM neutrino mass arises within the general framework of a warped extra dimension (dual to composite Higgs in 4D). It starts out as an attempt at implementing the high-scale seesaw mechanism. I will first carefully determine what the underlying dynamical picture really is. Motivated by this physical understanding, LHC signals of TeV-mass SM singlet neutrinos within a specific model for the electroweak gauge sector will be discussed. Some of these channels are similar to those studied in 4D left-right (LR) symmetric models, but nonetheless the two can be distinguished. While other signals are more characteristic of the 5D/composite framework, i.e., are absent in 4D LR models.

  19. APR

    14

    Friday

    Nuclear Theory/RIKEN Seminar

    "Effect of magnetic field on flow fluctuations in"

    Presented by Ajit M. Srivvastava

    2 pm, Small Seminar Room, Bldg. 510

    Friday, April 14, 2017, 2:00 pm

    Hosted by: 'Heikki Mantysaari'

    Very strong magnetic fields can arise in non-central heavy-ion collisions at ultrarelativistic energies, which may not decay quickly in a conducting plasma. We carry out magnetohydrodynamics simulations to study the effects of this magnetic field on the evolution of the plasma and on resulting flow fluctuations. Our results show that magnetic field leads to enhancement in elliptic flow, while flow fluctuations lead to reorganization of magnetic flux resulting in a transient increase in the local magnetic field. We also show generation of vorticity arising from nontrivial dependence of magnetosonic waves on pressure gradients and magnetic field direction. Magnetic field from collision of deformed nuclei shows very nontrivial features and can lead to qualitatively new effects on plasma evolutions. We discuss possibility of dynamo effect in the presence of vortices if any exotic high baryon density QCD phases are achieved in heavy-ion collisions.

  20. APR

    19

    Wednesday

    Particle Physics SB/BNL Joint Cosmo seminar

    "TBD"

    Presented by Kyle Story, Stanford

    3 pm, Stony Brook University

    Wednesday, April 19, 2017, 3:00 pm

  21. APR

    20

    Thursday

    Condensed-Matter Physics & Materials Science Seminar

    "Unpaired Spins in Superconductors: From Assassin to Enabler"

    Presented by Jeffrey Lynn, NIST Center for Neutron Research, National Institute of Standards and Technology

    11 am, Bldg. 734, ISB Conference Room 201 (upstairs)

    Thursday, April 20, 2017, 11:00 am

    Hosted by: '''Igor Zaliznyak'''

    The magnetic properties of superconductors have a rich and interesting history, and we will briefly review some highlights. Early work showed that even tiny concentrations of magnetic impurities destroyed the superconducting pairing through the exchange-driven spin depairing mechanism, prohibiting any possibility of magnetic order coexisting with superconductivity. The first exceptions to this rule were provided by the cubic rare-earth substituted CeRu2 alloys, followed by the ternary Chevrel-phase superconductors (e.g. HoMo6S8) and related compounds, where long range magnetic order coexists or competes with superconductivity. The very low magnetic ordering temperatures (~1 K) suggested that dipolar rather than exchange interactions dominate, thus (it was thought) allowing the coexistence. These materials also provided the first examples of the competition between ferromagnetism and superconductivity. In the newer borocarbide class of magnetic superconductors (e.g. ErNi2B2C), however, it became clear that the magnetic order is in fact exchange driven. The borocarbides also provided the first example of the spontaneous formation of flux quanta (vortices). For the cuprate and iron-based superconductors (formerly known as "high Tc") we now have come full circle, as the spins are not only tolerated but are intimately tied to the superconductivity. The "parent" cuprate systems are Mott-Hubbard antiferromagnetic insulators with very strong magnetic interactions that are two-dimensional in nature. These strong exchange interactions survive into the superconducting state, yielding highly correlated electrons that participate directly in the superconducting pairing. The "parent" materials of the new iron-based high TC superconductors are also antiferromagnets with very energetic spin excitations, and in the superconducting regime they form a "magnetic resonance" that is directly tied to the superconducting order parameter, ju

  22. APR

    20

    Thursday

    Particle Physics Seminar

    "Discovery of New Mikly Way Dwarf Galaxies in the Dark Energy Survey"

    Presented by Alex Drlica- Wagner, Fermilab

    3 pm, Small Seminar Room, Bldg. 510

    Thursday, April 20, 2017, 3:00 pm

    Hosted by: 'Erin Sheldon'

  23. APR

    26

    Wednesday

    YITP/HET Joint Seminar

    "TBA"

    Presented by John Donoghue, U. Mass Amherst

    2 pm, YITP Seminar Room, Stony Brook University

    Wednesday, April 26, 2017, 2:00 pm

  24. APR

    27

    Thursday

    RIKEN Lunch Seminar

    "Probing quantum entanglement at the Electron Ion Collider"

    Presented by Dima Kharzeev, BNL and Stony Brook University

    12:30 pm, Building 510, Room 20160

    Thursday, April 27, 2017, 12:30 pm

    Hosted by: 'Hiromichi Nishimura'

  25. APR

    27

    Thursday

    Particle Physics Seminar

    "Searching for Optical Counterparts to Gravitational Wave Events in the Dark Energy Survey"

    Presented by Jim Annis, Fermilab

    3 pm, Small Seminar Room, Bldg. 510

    Thursday, April 27, 2017, 3:00 pm

    Hosted by: 'Erin Sheldon'

  26. APR

    28

    Friday

    Condensed-Matter Physics & Materials Science Seminar

    "TBD"

    Presented by Martin Mourigal, Georgia Tech

    1:30 pm, Bldg. 734, ISB Conference Room 201 (upstairs)

    Friday, April 28, 2017, 1:30 pm

    Hosted by: ''Igor Zaliznyak''

    TBD

  27. MAY

    3

    Wednesday

    Joint YITP/HET Seminar

    "TBA"

    Presented by Tim Tait, UCI

    2 pm, Small Seminar Room, Bldg. 510

    Wednesday, May 3, 2017, 2:00 pm

    Hosted by: 'Amarjit Soni'

  28. MAY

    4

    Thursday

    Particle Physics Seminar

    "New MEG Results and Prospects for Improved Searches for Muon and Electron Number Violation in the Charged Sector"

    Presented by William Molzon, University of California, Irvine

    3 pm, Small Seminar Room, Bldg. 510

    Thursday, May 4, 2017, 3:00 pm

    Hosted by: 'Xin Qian'

    Searches for muon and electron number violation in the charged sector continue to be a sensitive probe of non Standard Model physics. I will give results of the full data-set of the MEG collaboration's search for muons decaying to electron plus photon and describe improvements to the MEG muon beam and apparatus that will improve sensitivity by a factor of ten in the next few years. I will also briefly review other experiments in the planning and early construction phases that are expected to improve sensitivity in related processes in the coming 5-10 years.

  29. MAY

    11

    Thursday

    RIKEN Lunch Seminar

    "> Probing quantum entanglement at the Electron Ion Collider"

    Presented by Dima Kharzeev, BNL and Stony Brook University

    12:30 pm, Building 510, Room 2-160

    Thursday, May 11, 2017, 12:30 pm

    Hosted by: 'Hiromichi Nishimura'

  30. MAY

    17

    Wednesday

    HET/RIKEN Seminars

    "TBA"

    Presented by Jonathan Kozaczuk, UMass Amherst

    2 pm, Small Seminar Room, Bldg. 510

    Wednesday, May 17, 2017, 2:00 pm

    Hosted by: 'Pier Paolo Giardino'

  31. JUL

    10

    Monday

    Office of Educational Programs Event

    "High School Research Program Begins"

    8:30 am, Hamilton Seminar Room, Bldg. 555

    Monday, July 10, 2017, 8:30 am

  1. Condensed-Matter Physics & Materials Science Seminar

    "Nematic quantum paramagnet and possible application to FeSe"

    Presented by Fa Wang, International Center for Quantum Materials Peking University, China

    Thursday, March 23, 2017, 11 am
    Bldg. 734, ISB Conference Room 201 (upstairs)

    Hosted by: ''Weiguo Yin''

    The nematic phases in iron pnictides are in close proximity to the stripe antiferromagnetic order, suggesting that magnetism is the driving force for the spontaneous 4-fold crystal rotation symmetry breaking. In contrast, bulk FeSe shows a nematic phase below 90K at ambient pressure, but has no magnetic long range order down to very low temperature. This prompts suggestions that the nematicity in FeSe is driven by some other mechanism. We argue that magnetic correlation can still drive nematic order in the absence of magnetic long-range order. By field theoretical considerations and exact diagonalization results on finite size lattices, we conclude that the paramagnetic phase in frustrated spin-1 J_1-J_2 model on square lattice is likely a "nematic quantum paramagnet", which breaks only the crystal 4-fold rotation symmetry. The prototype wavefunctions of such quantum ground states are horizontal(vertical) aligned spin-1 AKLT chains. We suggest that the local spins in FeSe may form this phase due to strong frustration. One unique consequence of this proposal is that the nematic paramagnetic phase will be close to both stripe and Neel antiferromagnetic order, and will thus host low but finite energy spin fluctuations at both ordering wavevectors. Reference: Fa Wang, S. A. Kivelson, and Dung-Hai Lee, Nat. Phys. 11, 959 (2015)

  2. Particle Physics Seminar

    "Heavy bosons: a probe into the unknown"

    Presented by Viviana Cavaliere, University of Illinois Champaign/Urbana

    Wednesday, March 22, 2017, 11 am
    Small Seminar Room, Bldg. 510

    Hosted by: ''Michael Begel''

    The large amount of high-energy proton-proton collision data at the LHC provides an unprecedented opportunity to search for new physics beyond the Standard Model at the TeV scale. The 2012 discovery of a 125 GeV Higgs boson opened a new door to understanding the universe, providing an exciting new tool to use in these searches, given it is now produced about once per second at the current collision rate. The talk will review recent ATLAS searches for physics beyond the Standard Model, focusing on the central role of processes with heavy bosons, including the Higgs, and the corresponding new possible signatures that range from spectacular new resonances to subtle changes in kinematic distributions.

  3. Nuclear Theory/RIKEN Seminar

    "Universal Transverse Momentum Dependent Fragmentation"

    Presented by Duff Neill, LANL

    Friday, March 17, 2017, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: 'Heikki Mantysaari'

    Fragmentation is the earliest and perhaps most interesting QCD jet observable, since it directly deals with the parton-hadron duality at the end of the QCD cascade. The most basic fragmentation observables all enjoy the property of being universal, in the sense that a sufficiently energetic parton that initiates the cascade factorizes from the rest of the event, so that the underlying soft structure of the event to a good approximation does not change the fragmentation spectrum. With the luminosities and resolution of modern detectors, we can begin to study the fragmentation process in three dimensions: both the energy spectrum and the transverse fluctuations to the collinear direction of initiating hard parton. However, when one wants to study the transverse fluctuations, one becomes very sensitive to the underlying jet definition, in particular, how the collinear direction is defined. Intuitive definitions of the jet direction, like the total momentum of the jet constituents, are inherently sensitive to soft processes, and can spoil the universality of the spectrum. I will discuss how a simple change in the jet definition removes this soft sensitivity, and allows one to study the intrinsic three dimensional structure of collinear splittings, which should be process independent.

  4. HET Lunch Discussions

    "Probing top-quark width using b-jet charge identification"

    Presented by Cen Zhang, BNL

    Friday, March 17, 2017, 12:15 pm
    Building 510, Room 2-160

    Hosted by: 'Christoph Lehner'

  5. RIKEN Lunch Seminar

    "TBA"

    Presented by Vladi Skokov, BNL

    Thursday, March 16, 2017, 12:30 pm
    Building 510, Room 2-160

    Hosted by: 'Hiromichi Nishimura'

  6. Particle Physics Seminar

    "Search for physics beyond the SM using multijet events with the ATLAS detector at the LHC"

    Presented by Haichen Wang, LBL

    Thursday, March 16, 2017, 11 am
    Small Seminar Room, Bldg. 510

    Hosted by: ''Michael Begel''

    Search for physics beyond the Standard Model (SM) has been one of the most important goals of the physics program at the Large Hadron Collider (LHC).Among all the final states, the multijet final state has long been considered as a challenging one for the search of physics beyond the SM due to its large background. Though, exciting new physics phenomena, such as the production of black hole as well as massive supersymmetric (SUSY) particles, may well result in signals in multijet final state. I present searches for physics beyond the SM using multijet events from 13 TeV collision data taken in 2015 and the first half of 2016 by the ATLAS experiment at the LHC. I focus on a search for the production of black hole and a search for massive supersymmetric particles decaying to many jets via R-Parity Violating (RPV) couplings. The two examples represent searches targeting physics beyond the SM at different mass scales, and therefore different analysis strategies are employed. These searches have greatly improved the sensitivity of the LHC to the black hole production and RPV SUSY scenarios, and they are complementary to searches using events of leptons, photons and missing transverse energy.

  7. Nuclear Physics Seminar

    "The sPHENIX Calorimeters: a proto-type story"

    Presented by Megan Connors, Georgia State University and RBRC

    Wednesday, March 15, 2017, 3:30 pm
    Small Seminar Room, Bldg. 510

    Hosted by: ''Jin Huang''

    sPHENIX, scheduled to start taking data in 2022 at RHIC, is a detector designed to probe the inner workings of the quark gluon plasma by measuring jets and their substructure, heavy flavor tagged jets and quarkonia. The design includes tracking systems, a solenoid magnet and calorimeter system. The calorimeter system, designed to measure the energy of jets, is comprised of an electromagnetic calorimeter, an inner hadronic calorimeter and and outer hadronic calorimeter. Prototypes of these detectors were built and tested in 2016. The results of the test beam show that the performance is well within the requirements set by the sPHENIX program. In addition, the results validate the GEANT4 simulation studies. The design of the sPHENIX calorimeter system, the test beam results from the calorimeter prototypes and additional studies will be presented

  8. HET/RIKEN Seminar

    "Hunting for New Leptonic Interactions at Colliders"

    Presented by Brian Shuve, SLAC

    Wednesday, March 15, 2017, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: ''Pier Paolo Giardino''

  9. Nuclear Theory Seminar

    "Nuclear Matter EoS and thermodynamic Properties of Skyrme models"

    Presented by Mareike Haberichter, Amherst

    Friday, March 10, 2017, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: 'Heikki Mantysaari'

    The Skyrme model is a candidate to describe the low energy regime of QCD where baryons and nuclei are topological excitations in a low-energy effective field theory of pions. The Skyrme model and its BPS variant (Skyrme model with a lower topological energy bound which is saturated) have been applied to the description of nuclei with notable recent success, e.g. quantitative description of Carbon-12 (including the Holye state and its rotational band) and of the low-lying energy spectrum of Oxygen-16. In this talk, we test Skyrme theories as models for nuclear matter at high densities and explore the thermodynamical properties of skyrmionic matter at zero temperature. We compute analytically the mean-field equation of state in the high and medium pressure regimes by applying topological bounds on compact domains. We identify which term in a generalised Skyrme model is responsible for which part in the equation of state and compare our findings with the corresponding results in the Walecka model. We find that the BPS submodel plays the dominant role at large densities. The BPS Skyrme model even allows us to derive thermodynamical variables and densities directly from the theory without having to perform a mean-field limit. This distinguishes the BPS Skyrme model from other models of nuclear matter where usually a mean-field limit has to be performed. Note that this is the first of two talks on Skyrme models and their predictions for nuclear matter at high densities. The second part on the description of neutron stars as Skyrme solitons will be given by Carlos Naya (Durham) on March, 24th at BNL.

  10. HET Lunch Discussions

    "Progress towards sub-percent precision for the muon g-2 HVP contribution from lattice QCD"

    Presented by Christoph Lehner, BNL

    Friday, March 10, 2017, 12:15 pm
    Building 510, Room 1-224

    Hosted by: 'Christoph Lehner'

  11. Particle Physics Seminar

    "WW measurements at CMS and perspectives for the HL-LHC"

    Presented by Rafael Coelho Lopes de Sa, FNAL

    Thursday, March 9, 2017, 3 pm
    Small Seminar Room, Bldg. 510

    Hosted by: 'Michael Begel'

    We will review recent diboson measurements and searches in the WW final state performed with the CMS detector. We will discuss the perspectives for some of these measurements with the full HL-LHC dataset. We will briefly describe some of the upgrades being designed for the CMS Silicon Tracker in order to operate in the high pileup environment of the HL-LHC while maintaining excellent performance for the final states discussed in this talk.

  12. RIKEN Lunch Seminar

    "Finite-Temperature Perturbative QCD confronts Lattice"

    Presented by Thorben Graf, University of Frankfurt

    Thursday, March 9, 2017, 12:30 pm
    Building 510, Room 1-224

    Hosted by: '''Heikki Mantysaari'''

    Since decades expressions for the thermodynamic potential were calculated perturbatively at finite temperature (and density) and pushed to higher orders. I review the current status of these efforts including resummation techniques and compare them to results of lattice Monte Carlo simulations and address unanswered questions. Finally, I present results for several thermodynamic quantities within the next-to-leading order calculation of the thermodynamic potential at finite T and \mu including non-vanishing quark masses.

  13. Condensed-Matter Physics & Materials Science Seminar

    "Transport and signatures of Mottness versus Hundness in strongly correlated metals"

    Presented by Xiaoyu Deng, Rutgers

    Thursday, March 9, 2017, 11 am
    Bldg. 734, ISB Conference Room 201 (upstairs)

    Hosted by: ''Gabi Kotliar''

    In this seminar I will focus two fundamental aspects of strongly correlated metals: the transport properties and the origin of correlation. Recent advances enables us to study quantitatively various properties of two archetypal correlated oxides, vanadium oxides and ruthenates, using the LDA+DMFT method. Both are strongly correlation, these two materials are quite different in their origins of correlation: V2O3 is proximate to a Mott state while Sr2RuO4 is not. Thus V2O3 is regarded as a prototype Mott system, while recent studies emphasize that Sr2RuO4 belongs to new category termed "Hund's metal" in which Hund's coupling is responsible for the correlations. We carried out a systematical theoretical study on the transport properties of V2O3 and ruthenates family. Our computed resistivity and optical conductivity are in very good agreement with experimental measurements, which clearly demonstrates that the strong correlation dominates the transport of this material , despite their origin of correlation. We demonstrated that "resilient quasiparticles" dominates the transport. Furthermore by expressing the resistivity in terms of an effective plasma frequency and an effective scattering rate, we uncover the so-called "hidden Fermi liquid" behavior. We identified signatures of Mottness and Hundness by a comparative study of V2O3 and Sr2RuO4. In V2O3 the low temperature coherent resonance emerges from the pseudogap regime appearing at high temperature between incoherent peaks, while in Sr2RuO4, it emerges from a single incoherent peak with large finite value at the Fermi level.. We show that these two contrasting scenarios features interesting behaviors in the local properties of correlated atoms including charge fluctuations, spin and orbit susceptibility and entropy. The findings shed new lights on the understanding of strongly correlated metals.

  14. Particle Physics Seminar

    "Electroweak Physics at ATLAS"

    Presented by Jake Searcy, Michigan

    Wednesday, March 8, 2017, 11 am
    Small Seminar Room, Bldg. 510

    Hosted by: 'Michael Begel'

    Electroweak symmetry breaking is a central pillar of the standard model, and experimentally one of the least understood. Many physics scenarios predict modifications to this mechanism resulting in new particles or interactions. This talk will summarize our knowledge of the electroweak sector with a particular focus on the interactions between W-bosons.

  15. Environmental & Climate Sciences Department Seminar

    "Sub 2 nm Particle Characterization in Systems with Aerosol Formation and Growth"

    Presented by Yang Wang, Washington University

    Wednesday, March 8, 2017, 10 am
    Conference Room Bldg 815E

    Hosted by: 'Jian Wang'

    Aerosol science and technology enable continual advances in material synthesis and atmospheric pollutant control. Among these advances, one important frontier is characterizing the initial stages of particle formation by real time measurement of particles below 2 nm in size. Sub 2 nm particles play important roles by acting as seeds for particle growth, ultimately determining the final properties of the generated particles. Tailoring nanoparticle properties requires a thorough understanding and precise control of the particle formation processes, which in turn requires characterizing nanoparticle formation from the initial stages. This work pursued two approaches in investigating incipient particle characterization in systems with aerosol formation and growth: (1) using a high-resolution differential mobility analyzer (DMA) to measure the size distributions of sub 2 nm particles generated from high-temperature aerosol reactors, and (2) analyzing the physical and chemical pathways of aerosol formation during combustion. Part. 1. Particle size distributions reveal important information about particle formation dynamics. DMAs are widely utilized to measure particle size distributions. However, our knowledge of the initial stages of particle formation is incomplete, due to the Brownian broadening effects in conventional DMAs. The first part of this presentation discusses the applicability of high-resolution DMAs in characterizing sub 2 nm particles generated from high-temperature aerosol reactors, including a flame aerosol reactor (FLAR) and a furnace aerosol reactor (FUAR). Comparison against a conventional DMA (Nano DMA, Model 3085, TSI Inc.) demonstrated that the increased sheath flow rates and shortened residence time indeed greatly suppressed the diffusion broadening effect in a high-resolution DMA (half mini type). The incipient particle size distributions were discrete, suggesting the formation of stable clusters that may be intermediate phases betw

  16. Physics Colloquium

    "Snapping pictures of the proton with heavy ions"

    Presented by Bjoern Schenke, BNL

    Tuesday, March 7, 2017, 3:30 pm
    Large Seminar Room, Bldg. 510

    Hosted by: ''Robert Pisarski''

    I will present an overview of recent theoretical developments related to the science program at the Relativistic Heavy Ion Collider at Brookhaven National Laboratory and the Large Hadron Collider at CERN. Beginning from heavy ion collisions and the creation of the quark gluon plasma, the most perfect and hottest fluid every created on earth, I will proceed to discuss smaller collision systems, like proton+lead collisions. The experimental data from these show strikingly similar features to heavy ion collisions and I will discuss their possible origins. If the physics in these small systems is also dominated by the fluid dynamic behavior of the created matter, experimental measurements combined with theoretical models give us unprecedented access to the fluctuating shape of the proton.

  17. NSLS-II Engineering Seminar Series

    "High-Resolution Monochromator Development for Nuclear Resonant Scattering"

    Presented by Thomas Toellner, X-Ray Science Division,

    Tuesday, March 7, 2017, 2 pm
    John Dunn Seminar Room, Bldg. 463

    Hosted by: ''Sushil Sharma and Mary Carlucci-Dayton''

    High-resolution monochromators (HRMs) are key components at nuclear resonant scattering beamlines, and their development at the APS has been ongoing for decades. They are used to resolve the frequency spectrum of isotope-specific atomic dynamics using nuclear resonant vibrational spectroscopy and to reduce the enormous electronic charge scattering that accompanies nuclear excitation using synchrotron radiation. The latter allowing the measurement of hyperfine fields using synchrotron Moessbauer spectroscopy. The narrow line-widths (neV) associated with nuclear resonances also offer an excellent diagnostic tool for the characterization of HRMs, and have greatly facilitated their development. HRMs with ultra-high energy-resolution exposed the need for greater energy-alignment stability and prompted the development of cryo-stabilization. A recent prototype sub-meV-bandwidth monochromator for hard X-rays that implements cryo-stabilization has been built that displays a 100-fold improvement in energy-alignment stability over other designs. This unprecedented level of control allows one to observe the intrinsic factors that limit the energy resolution obtainable with silicon. I will present the principle design aspects of this prototype along with its performance, and discuss what has been learned.

  18. Nuclear Physics Seminar

    "Collectivity in small collision systems, what is it?"

    Presented by Jiangyong Jia, BNL and Stony Brook University

    Tuesday, March 7, 2017, 11 am
    Small Seminar Room, Bldg. 510

    Hosted by: 'Jin Huang'

    In recent years, there been rapid progresses in our understanding of the long-range ridge in small collision system at RHIC and LHC. I will discuss the nature of collectivity (flow) driving the ridge, as well as the dominating non-collective (or non-flow) background that complicates the extraction of the ridge. I shows that the standard multi-particle cumulant method, often used to defined collectivity in heavy ion collisions, is overwhelmed by non-collective background in pp and low multiplicity pPb collisions. This problem is resolved with an alternative method based on two or more subevents separated in pseudorapidity (η), and therefore offers a robust data-driven definition of collectivity based on the existence of long-range azimuthal correlations between multiple distinct η ranges. With this new cumulant method, we are able to probe reliably the event-by-event fluctuation of collectivity in small collision systems.

  19. HET Lunch Discussions

    "Lattice Calculation of Nucleon Electric Dipole Moments"

    Presented by Sergey Syritsyn, Stony Brook

    Friday, March 3, 2017, 12:15 pm
    Building 510, Room 2-160

    Hosted by: '''Christoph Lehner'''

    Searches for permanent electric dipole moments (EDM) of neutrons, protons, and nuclei are the most sensitive probes for CP violation, which is necessary for baryogenesis. Currently developed experiments will improve bounds on the neutron EDM by 2-3 orders of magnitude. However, to put constraints on CP-violating interactions, nonperturbative QCD calculations of nucleon structure are necessary. I will present some recent developments in lattice calculations of nucleon EDMs induced by quark-gluon CP-odd interaction

  20. NSLS-II Friday Lunchtime Seminar Series

    "Elemental Concentration and Size Apportionment of Combustion Particles from Wood-fired Appliances" and "Creating Methods for Material Design and Synthesis for Microporous and Mesoporous Materials"

    Presented by Monica Gray-Georges and Nicholas Brunelli, Lincoln University of Pennsylvania and Ohio State University

    Friday, March 3, 2017, 12 pm
    NSLS-II Bldg 743 (LOB 3), room 156

    Hosted by: ''Ben Ocko and Shirish Chodankar''

  21. Condensed-Matter Physics & Materials Science Seminar

    "Ab Initio electronic structure of solids: correlation effects beyond the GW method"

    Presented by Andrei Kutepov, Rutgers University

    Thursday, March 2, 2017, 1:30 pm
    Bldg. 734, ISB Conference Room 201 (upstairs)

    Hosted by: ''''Gabi Kotliar''''

    TBA

  22. RIKEN Lunch Seminar

    "Generalized Nambu-Goldstone theorem"

    Presented by Yoshimasa Hidaka, RIKEN

    Thursday, March 2, 2017, 12:30 pm
    Building 510, Room 2-160

    Hosted by: ''Hiromichi Nishimura''

    Symmetry and its spontaneous breaking are of basic importance for understanding the low energy physics in many-body systems. When a continuum symmetry is spontaneously broken, there exist a zero mode called Nambu-Goldstone (NG) mode, which is well developed in Lorentz invariant systems. In contrast, in non-Lorentz invariant systems, the NG theorem has not been well developed. In this talk, we discuss the recent progress in generalization of NG theorem in non-relativistic systems, open systems, and systems with higher form symmetries.

  23. Particle Physics Semiar SB/BNL Joint Cosmo Seminar

    "TBA"

    Presented by Will Farr, Birmingham

    Wednesday, March 1, 2017, 1:30 pm
    Stony Brook University

  24. Physics Colloquium

    "The Experimental Challenge of 21 cm Cosmology"

    Presented by Miguel Morales, University of Washington

    Tuesday, February 28, 2017, 3:30 pm
    Large Seminar Room, Bldg. 510

    Hosted by: ''Andrei Nomerotski''

  25. RIKEN Lunch Seminar

    "The Kibble-Zurek scaling for the Entanglement Entropy on the scalar field in 1+1 dimension"

    Presented by Akio Tomiya, CCNU

    Monday, February 27, 2017, 12:30 pm
    Building 510, Room 2-160

    Hosted by: 'Hiromichi Nishimura'

    The entanglement entropy is a candidate of an entropy in Non-equilibrium physics and recently, relaxation or thermalization is studied through the entanglement entropy with quamtum quenching, which is sudden change of parameter(s) in the Hamiltonian of the system. Global quantum quench with a finite rate which crosses critical points is known to lead to universal scaling of correlation functions as functions of the quench rate. We explore scaling properties of the entanglement entropy of a subsystem of a scaler field on the lattice, harmonic chain, during a mass quench which asymptotes to finite constant values at early and late times and for which the dynamics is exactly solvable. Both for fast and slow quenches we find that the entanglement entropy has a constant term plus a term proportional to the subsystem size. For slow quenches, the constant piece is consistent with Kibble- Zurek predictions. Furthermore, the quench rate dependence of the extensive piece enters solely through the instantaneous correlation length at the Kibble-Zurek time, suggesting a new scaling hypothesis similar to that for correlation functions. This talk is based on arXiv:1702.04359.

  26. Nuclear Theory Seminar

    "A Complete Diagrammatic Implementation of the Kinoshita-Lee-Nauenberg Theorem at Next-to-Leading Order"

    Presented by Will Horowitz, University of Cape Town

    Friday, February 24, 2017, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: ''Heikki Mantysaari''

    We show for the first time in over 50 years how to correctly apply the Kinoshita-Lee-Nauenberg theorem diagrammatically in a next-to-leading order scattering process. We improve on previous works by including all initial and final state soft radiative processes, including absorption and an infinite sum of partially disconnected amplitudes. Crucially, we exploit the Monotone Convergence Theorem to prove that our delicate rearrangement of this formally divergent series is correct. This rearrangement yields a factorization of the infinite contribution from the initial state soft photons that then cancels in the physically observable cross section. We derive the first complete next-to-leading order, high-energy Rutherford elastic scattering cross section in the MSbar renormalization scheme as an explicit example of our procedure.

  27. HET Lunch Discussions

    "Inclusive tau decays"

    Presented by Taku Izubuchi, BNL

    Friday, February 24, 2017, 12:15 pm
    Building 510, Room 2-160

    Hosted by: 'Christoph Lehner'

  28. RIKEN Lunch Seminar

    "Path-integral formula for local thermal equilibrium"

    Presented by Masaru Hongo, RIKEN

    Thursday, February 23, 2017, 12:30 pm
    Building 510, Room 2-160

    Hosted by: ''Hiromichi Nishimura''

    Relativistic hydrodynamics is formulated based on the assumption that systems are almost in local thermal equilibrium. However, a quantum field theoretical way to handle such a locally thermalized system has not been clearly clarified. In this study, we develop a complete path-integral formulation of relativistic quantum fields in local thermal equilibrium, which brings about the emergence of thermally induced curved spacetime. The obtained path-integral formula for local thermal equilibrium enables us to derive nondissipative part of hydrodynamic constitutive relations based on symmetry arguments. As one application, we discuss a field theoretical derivation of anomalous hydrodynamics which captures the chiral magnetic/vortical effects.

  29. HET/RIKEN Seminar

    "Few-body systems in QCD"

    Presented by Raul A. Briceno, JLAB

    Wednesday, February 22, 2017, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: 'Mattia Bruno'

  30. Nuclear Theory/RIKEN Seminar

    "High energy QCD at NLO"

    Presented by Michael Lublinsky, Ben-Gurion University

    Friday, February 17, 2017, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: 'Chun Shen'

  31. HET Lunch Discussions

    "B-decay Anomalies in a Composite Leptoquark Model"

    Presented by Christopher Murphy, BNL

    Friday, February 17, 2017, 12:15 pm
    Building 510, Room 2-160

    Hosted by: ''Christoph Lehner''

    The collection of a few anomalies in semileptonic $B$-decays, especially in $b \to c \tau \bar{\nu}$ invites us to speculate about the emergence of some striking new phenomena, perhaps interpretable in terms of a weakly broken $U(2)^n$ flavor symmetry and of leptoquark mediators. Here we aim at a partial UV completion of this interpretation by generalizing the minimal composite Higgs model to include a composite vector leptoquark as well. Reference: arXiv:1611.04930 w/ R. Barbieri and F. Senia

  32. RIKEN Lunch Seminar

    "The search for gluon saturation in pA collisions and at the EIC"

    Presented by Bowen Xiao, Central China Normal University

    Thursday, February 16, 2017, 12:30 pm
    Building 510, Room 2-160

    Hosted by: 'Heikki Mantysaari'

    In this talk, I plan to discuss the recent theoretical progress towards the exploration of the gluon saturation phenomenon in pA collisions and at the future EIC. Two important pillars of this exploration are the single inclusive forward hadron productions and forward dijet correlations, which have both been computed up to one-loop order within the small-x factorization formalism. Complementary measurements in pA collisions and at the EIC can help us measure small-x gluon distributions and test the generalized small-x factorization. In addition, DIS diffractive dijet process is another interesting process which is sensitive to the dipole Wigner gluon distributions. This process can provide us 3D tomographic images of low-x gluons inside high energy protons and nuclei.

  33. HET/RIKEN Seminar

    "Extracting scattering observables and resonance properties from lattice QCD"

    Presented by Maxwell T. Hansen, Helmholtz Institute Mainz

    Wednesday, February 15, 2017, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: 'Mattia Bruno'

  34. Particle Physics Seminar - SB/BNL Joint Cosmo Seminar

    "TBA"

    Presented by Adrian Liu, Berkeley

    Wednesday, February 15, 2017, 1:30 pm
    Stony Brook University

  35. Physics Colloquium

    "Thermalization and hydrodynamization in heavy-ion collisions at high energies"

    Presented by Aleksi Kurkela, CERN and Univ. of Stavenger

    Tuesday, February 14, 2017, 3:30 pm
    Large Seminar Room, Bldg. 510

    Hosted by: ''Robert Pisarski''

    Describing heavy-ion collisions as hydrodynamical explosions of liquid of quarks and gluons has been a tremendous phenomenological success. A major uncertainty in such modeling arises from what happens during the first 1fm/c of the evolution during which the system is far from local thermal equilibrium. I will describe how the postcollision debris start behaving hydrodynamically, and how the phenomenological modeling of the prehydrodynamical evolution can be improved.

  36. Condensed-Matter Physics & Materials Science Seminar

    "Thermalization and chaos in quantum systems"

    Presented by Sriram Ganeshan, Stony Brook University

    Tuesday, February 14, 2017, 1:30 pm
    Bldg. 734, ISB Conference Room 201 (upstairs)

    Hosted by: '''Robert Konik'''

    Thermalization, a common phenomenon in various physical settings, can naturally fail in certain isolated disordered quantum systems, challenging basic tenets of quantum statistical mechanics. Many body localization (MBL) is a canonical example of such an intriguing scenario and, therefore, attracted tremendous attention from condensed matter, statistical physics, and atomic physics communities. Considerable effort has recently gone into establishing the existence of the MBL phase, and the nature of dynamical phase transition from MBL to the thermal phase. However, understanding instabilities to the MBL phase that may lead to the complete or partial restoration of thermalization is still an open question. In this talk, I would focus on two such instabilities to the MBL phase coming from single particle mobility edge and the presence of extensive degeneracy in the many body spectrum. The goal is to identify the most robust form of MBL (in the presence of instabilities) to gain insight into the mechanisms of quantum thermalization.

  37. HET Seminar

    "QCD with Minimally Doubled Fermions"

    Presented by Johannes Weber, TUM

    Tuesday, February 14, 2017, 1 pm
    Building 510, Room 2-160

    Hosted by: ''Mike Creutz''

  38. HET Lunch Discussions

    "TBA"

    Presented by Taku Izubuchi, BNL

    Friday, February 10, 2017, 12:15 pm
    Building 510, Room 2-160

    Hosted by: 'Christoph Lehner'

  39. HET Seminar

    "TBA"

    Presented by Johannes Weber

    Thursday, February 9, 2017, 3 pm
    Small Seminar Room, Bldg. 510

    Hosted by: ''Mike Creutz''

  40. Environmental & Climate Sciences Department Seminar

    "The Impact of Organic Aerosol Volatility on Aerosol Microphysics for Global Climate Modeling Applications"

    Presented by Yuchao 'Chloe' Gao, NASA Goddard Institute for Space Studies, China

    Thursday, February 9, 2017, 11 am
    Conference Room Bldg 815E

    Hosted by: 'Robert McGraw'

    A newly developed box model, MATRIX-VBS [Gao et al., 2017], includes the volatility-basis set (VBS) framework in an aerosol microphysical scheme MATRIX (Multiconfiguration Aerosol TRacker of mIXing state) [Bauer et al., 2008], which is a module within GISS ModelE that resolves aerosol mass and number concentrations and aerosol mixing state. By including the gas-particle partitioning and chemical aging of semi-volatile organic aerosol in MATRIX, we were able to examine its effects on the growth, composition and mixing state of particles. MATRIX-VBS is unique and advances the representation of organic aerosols in Earth system models by greatly improving the traditional and very simplistic treatment of organic aerosols as non-volatile and with a fixed size distribution. Idealized cases representing Beijing, Mexico City, a Finnish and a Southeast U.S. forest were simulated, and we investigated the evolution of mass concentrations and volatility distributions for organic species across the gas and particle phases, as well as their mixing state among aerosol populations. To test and simplify the model, a Monte-Carlo analysis is performed to pin point which processes affect organics the most under varied chemical and meteorological conditions. Since the model's parameterizations have the ability to capture a very wide range of conditions, all possible scenarios on Earth across the whole parameter space, including temperature, humidity, location, emissions and oxidant levels, are examined. These simulations provide information on which parameters play a critical role in the aerosol distribution and evolution in the atmosphere and which do not, and that will facilitate the simplification of the box model, an important step in its implementation in the global model GISS ModelE as a module.

  41. Particle Physics Seminar - SB/BNL Joint Cosmo Seminar

    "TBA"

    Presented by Tim Eifler, JPL/Caltech

    Wednesday, February 8, 2017, 1:30 pm
    Stony Brook University

  42. HET Lunch Discussions

    "The Coming Armageddon - Upcoming Cyber and Other Changes"

    Presented by Thomas Throwe, BNL

    Friday, February 3, 2017, 12:15 pm
    Building 510, Room 2-160

    Hosted by: '''Christoph Lehner'''

  43. Particle Physics Seminar

    "Di-Higgs at the LHC: Current Status and Future Prospects"

    Presented by John Alison, University of Chicago

    Thursday, February 2, 2017, 3 pm
    Small Seminar Room, Bldg. 510

    Hosted by: 'Michael Begel'

    I will discuss motivations for searching for di-Higgs production at the LHC. Recent results and projected sensitivities will be presented with particular emphasis on the dominant hh->4b channel

  44. HET Seminar

    "Exploring the Low Mass Frontier in Dark Matter Direct Detection"

    Presented by Tongyan Lin, LBL

    Wednesday, February 1, 2017, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: ''Amarjit Soni''

  45. Particle Physics Seminar - SB/BNL Joint Cosmo Seminar

    "TBA"

    Presented by Elisabeth Krause, SLAC

    Wednesday, February 1, 2017, 1:30 pm
    Stony Brook University

  46. Nuclear Theory/RIKEN Seminar

    "What shines brighter, Glasma or Quark-Gluon Plasma?"

    Presented by Naoto Tanji, University of Heidelberg

    Friday, January 27, 2017, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: ''Heikki Mantysaari''

    Recent classical-statistical numerical simulations have established the "bottom-up" thermalization scenario of Baier et al. as the correct weak coupling effective theory for thermalization in ultrarelativistic heavy-ion collisions. I will talk on a parametric study of photon production in the various stages of this bottom-up framework to ascertain the relative contribution of the off-equilibrium "Glasma" relative to that of a thermalized Quark-Gluon Plasma. Taking into account the constraints imposed by the measured charged hadron multiplicities at RHIC and the LHC, we find that Glasma contributions are important especially for large values of the saturation scale at both energies. Furthermore, I will report on first kinetic simulations of photon production in the expanding Glasma that will quantify our estimates.

  47. HET Lunch Discussions

    "EFTs and the Higgs"

    Presented by Sally Dawson, BNL

    Friday, January 27, 2017, 12:15 pm
    Building 510, Room 2-95

    Hosted by: 'Christoph Lehner'

  48. Particle Physics Seminar

    "New Models of Baryogenesis"

    Presented by Dr. David McKeen, University of Pittsburgh

    Thursday, January 26, 2017, 3 pm
    Small Seminar Room, Bldg. 510

    Hosted by: ''Hooman Davoudiasl''

    I will describe a new mechanism for creating the matter-antimatter asymmetry of the Universe at low temperatures, i.e. below the QCD confinement temperature, involving the CP-violating oscillation of fermions made of strongly interacting particles. I will also make connections to neutron-antineutron oscillations, clearing up issues that exist in the literature. Novel experimental tests will be discussed.

  49. Condensed-Matter Physics & Materials Science Seminar

    "Anion-based approaches to engineering functionality in perovskite oxide heterostructures"

    Presented by Steve May, Drexel University

    Thursday, January 26, 2017, 1:30 pm
    ISB Bldg. 734, Conf. Room 201 (upstairs)

    Hosted by: ''Mark Dean''

    Scientific interest in ABO3 perovskite oxides remains intense due to the wide range of physical behavior present in these materials. The ability to control the position, occupation, and composition of the anion site has recently emerged as a new route to tune properties in epitaxial perovskites. This talk will focus on recent and ongoing efforts aimed at developing anion-based approaches to tailor electronic, optical and magnetic properties in oxide heterostructures. First, I will discuss how the position of the oxygen anions can be controlled to stabilize non-bulk-like bond angles and lengths, thereby modifying electronic and magnetic behavior in manganite films and superlattices. In the second half of the talk, I will describe efforts focused on controlling the occupation and composition of the anion site, including reversible oxidation/reduction in thin La1/3Sr2/3FeO3-? films and topotactic fluorination reactions to realize oxyfluoride films

  50. RIKEN Lunch Seminar

    "From small to moderate-x: beyond the eikonal approximation"

    Presented by Andrey Tarasov, BNL

    Thursday, January 26, 2017, 12:30 pm
    Building 510, Room 1-224

    Hosted by: '''Hiromichi Nishimura'''

    In recent years significant progress has been made in our understanding of the small-x physics beyond the eikonal approximation. Rigorous analysis of the dependence on the transverse momentum helps us better understand not only physics of the Regge limit, but to connect it to the kinematic limit of the moderate-x as well. I'll describe the technique we used in calculation of TMD evolution observed in the Drell-Yan process and present some recent results.

  51. Joint YITP/HET Seminar

    "muon colliders"

    Presented by Mario Greco, Frascati

    Wednesday, January 25, 2017, 2:30 pm
    YITP Seminar Room

  52. C-AD Accelerator Physics Seminar

    "Engineering Studies Related to Nuclear Molecular Imaging"

    Presented by Dr. Dohyun Kim, Weill Cornell Medicine

    Tuesday, January 24, 2017, 4 pm
    Bldg 911B, Large Conf. Rm., Rm. A202

    One of the major uses of radioisotopes is for nuclear molecular imaging using a variety of radiotracers. It is a multidisciplinary science that includes physics, chemistry, biology, computer science, mathematics and medicine with the goal of improving human life. These radiotracers can be used in a PET scanner (or other types of scanners) to generate a three dimensional image of the inside of the human body. PET scanners are used mainly for brain research and cancer detection. The goal of positron emission tomography (PET) is to generate in-vivo images from patients with a disease or abnormal condition. PET scanners detect the 511 keV annihilation gamma rays that are produced when a positron from a nuclear decay interacts with an electron. The gamma rays are given off at nearly 180° from each other and can be detected as originating along a straight line if they arrive at the detectors within a given time interval known as the coincidence window. I will describe the development of a very novel PET scanner with very high resolution using CZT solid state detectors. A novel feature of this system design is that the CZT detectors are rotated 90 degrees from their conventional orientation to use the C/A ratio such that the depth direction is oriented tangentially to the circular FOV of the tomograph. Thus the expected ~0.25 ? depth resolution of the detectors can be used to provide ultra-high resolution in the transaxial plane. The CdZnTe detector PET scanner we developed has a 600 micron FWHM image resolution and an excellent energy resolution of < 2 % FWHM. I will also discuss the development and fabrication of gas phase 11CO2 to 11CO, H11CN, 11CH3I and 11CH3OTf auto synthesis system. These systems are used to generate the radiotracers used with PET. The design and fabrication involve understanding the chemistry, utilizing the physics of flow and transport and engineering a final solution that incorporates these effects.

  53. Condensed-Matter Physics & Materials Science Seminar

    "Ultrafast Dynamical Phenomena in Nanostructural Materials by 4D Electron Microscopy"

    Presented by Xuewen Fu, California Institute of Technology

    Tuesday, January 24, 2017, 2 pm
    Building 480, Conference Room

    Hosted by: ''Yimei Zhu''

  54. Condensed-Matter Physics & Materials Science Seminar

    "Creation and Control of Low Dimensional Electron System in Transition Metal Oxides"

    Presented by Milan Radovic, Paul Scherer Institut, Switzerland

    Monday, January 23, 2017, 11 am
    Building 734, conference room 201

    Hosted by: '''Cedomir Petrovic'''

    Transition Metal Oxides (TMOs) exhibit unique and multifunctional electronic properties (such as high-temperature superconductivity, colossal magnetoresistance, metal-insulator transitions, etc.) directly related to the spin and orbital degrees of freedom of the transition metal d-states. Furthermore, their iso-structural nature permits realization of heterostructures where novel unexpected electronic properties take place. Engineering transition metal oxide surfaces and interfaces carries the potential for achieving new physical properties that radically differ from those of the constituent bulk materials. This is the case of oxide-lowDEGs, which recently showed extraordinary occurrences, including interfacial superconductivity, magnetism, large tuneable spin-orbit coupling and indications of topological states. In my talk, I will present recent spin resolved Angle Resolved Photoemission Spectroscopy (ARPES) measurements of the low dimensional electron gas at SrTiO3 [1, 2, 3], TiO2-anatase and Sr1-xBaxTiO3 showing that these materials have capability for the realization of TMO based electronic device. References: [1] N. C. Plumb, M. Salluzzo, E. Razzoli, M. Månsson, M. Falub, J. Krempasky, C. E. Matt, J. Chang, J. Minár, J. Braun, H. Ebert, B. Delley, K.-J. Zhou, C. Monney, T. Schmitt, M. Shi, J. Mesot1, C. Quitmann, L. Patthey, M. Radovic, Phys. Rev. Lett. 113, 086801 (2014). [2] A. F. Santander-Syro, F. Fortuna, C. Bareille, T. C. Rodel, G. Landolt, N. C. Plumb, J. H. Dil, and M. Radovic, Nature Materials, 13, 1085–1090 doi:10.1038/nmat4107 (2014). [3] Z. Wang, S. McKeown Walker, A. Tamai, Z. Ristic, F.Y. Bruno, A. de la Torre, S. Ricco, N.C. Plumb, M. Shi, P. Hlawenka, J. Sanchez-Barriga, A. Varykhalov, T.K. Kim, M. Hoesch, P.D.C. King, W. Meevasana, U. Diebold, J. Mesot, M. Radovic, and F. Baumberger, Nature Materials 15, 835–839 (2016) doi:10.1038/nmat4623 (2016).

  55. Nuclear Theory Seminar

    "Helicity Evolution at Small x and the Proton Spin"

    Presented by Yuri Kovchegov, Ohio State University

    Friday, January 20, 2017, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: ''Heikki Mantysaari''

    We construct small-x evolution equations which can be used to calculate quark and anti-quark helicity TMDs and PDFs, along with the g_1 structure function. These evolution equations resum powers of alpha_s ln^2 (1/x) in the polarization-dependent evolution along with the powers of alpha_s ln (1/x) in the unpolarized evolution which includes saturation effects. The equations are written in an operator form in terms of polarization-dependent Wilson line-like operators. While the equations do not close in general, they become closed and self-contained systems of non-linear equations in the large-N_c and large-N_c & N_f limits. After solving the large-N_c equations numerically we obtain the following small-x asymptotics for the flavor-singlet g_1 structure function along with quarks helicity PDFs and TMDs (in absence of saturation effects): g_1^S (x, Q^2) ~ \Delta q^S (x, Q^2) ~ g_{1L}^S (x, k_T^2) ~ ( 1/x )^{alpha_h} \approx t( 1/x )^{2.31 \sqrt{\alpha_s N_c/(2pi}} This result is valid for all flavors. We also give an estimate of how much of the proton's spin may reside at small x and what impact this has on the so-called ``spin crisis.'' This work would help one better understand longitudinal polarization data to be obtained at the proposed Electron-Ion Collider (EIC).

  56. HET Lunch Discussions

    "epsilin, epsilon'....& the K-UT"

    Presented by Amarjit Soni, BNL

    Friday, January 20, 2017, 12:15 pm
    Building 510, Room 2-160

    Hosted by: ''Christoph Lehner''

  57. Center for Functional Nanomaterials Seminar

    "Amyloid Self-Assembly and Sequence-Dependent Interactions with Plasmonic Nanoparticles"

    Presented by Shih-Ting (Christine) Wang, Imperial College London, United Kingdom

    Thursday, January 19, 2017, 2 pm
    CFN, Bldg 735, Conference Room A, 1st Floor

    Hosted by: ''Oleg Gang''

    Nanoparticles (NPs) have been used to inhibit or modulate the peptide fibrillation as a potential therapeutic strategy and to understand the molecular mechanisms of amyloid diseases. Particularly, gold nanoparticles (AuNPs) have been widely used to study peptide/inorganic NP interactions due to the tunable size, surface and plamonic properties. In this talk, I will present the study of interaction of AuNPs with islet amyloid polypeptide (IAPP), which features in type 2 diabetes pathogenesis by self-assembly into fibrils and peptide-induced disruption of cell membranes. Amyloid fibrils share a distinct β-sheet structure, with the structural diversity controlled by the amino acid sequence. To elucidate the key mechanisms of amyloid self-assembly and provide unique viewpoints on the interactions with NPs, polymorphic fibril structures will firstly be discussed using amyloidogenic peptides that are designed based on the IAPP sequence. The observed amyloid fibrillation and hydrogelation controlled by the peptide structure also led to a proposed relationship between amyloid structure and self-assembly behaviour. Next, I will present the systematic study of IAPP/AuNP interactions, in which the strong binding is initiated by the metal-binding sequence in the hydrophilic peptide domain. Structural transition accelerated in a NP size-dependent manner also implies a facet-dependent IAPP/AuNP interaction. Based on these findings, liquid cell transmission electron microscopy was used for direct visualisation of the dynamic growth of AuNPs in presence of IAPP fibrils. The results show growth of branch(star)-shaped AuNPs in the presence of IAPP fibrils, suggesting a preferred nucleation site for Au binding and subsequent growth on the amyloid template.

  58. RIKEN Lunch Seminar

    "Vector mesons and chiral symmetry restoration"

    Presented by Fabian Rennecke, Heidelberg University

    Thursday, January 19, 2017, 12:30 pm
    Building 510, Room 2-160

    Hosted by: 'Hiromichi Nishimura'

    Vector mesons play a prominent role for the detection of chiral symmetry restoration in the quark-gluon plasma since their in-medium modifications are directly observable in dilepton spectra. However, a direct connection between their in-medium modifications and chiral symmetry restoration remains elusive. To shed some light on this, I will first address the question how chiral symmetry breaking and the light (vector) mesons emerge from the underlying quark-gluon dynamics. Then, I will present preliminary results on the in-medium spectral functions of the rho and a1 mesons obtained from analytic continuation of Euclidean two-point functions.

  59. Particle Physics Seminar

    "Ultra-Fast Silicon Detector for precise timing at CMS"

    Presented by Nicolo' Cartiglia, Torino

    Thursday, January 19, 2017, 11 am
    Small Seminar Room, Bldg. 510

    Hosted by: 'Alessandro Tricoli'

    In this seminar I will first review the physics case for a hermetic timing detector for charge particles to be installed in CMS in the years 2024-25 in preparation of the High Luminosity upgrade of the LHC accelerator (HL-LHC). Then I will present the possible technologies currently under studies for the timing detector and then I will concentrate on explaining the basics principles of Ultra-fast Silicon Detectors and their performances. I will conclude with a brief outline of the future R&D steps for the construction of the timing detector.

  60. HET Seminar

    "Phenomenology of Enhanced Light Quark Yukawa Couplings and the Wh Charge Asymmetry"

    Presented by Felix Yu, Mainz

    Wednesday, January 18, 2017, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: ''Amarjit Soni''

  61. Particle Physics Seminar - SB/BNL Joint Cosmo Seminar

    "Hunting down systematics in modern galaxy surveys"

    Presented by Mohammadjavad Vakili, NYU

    Wednesday, January 18, 2017, 1:30 pm
    Stony Brook University

    With the next generation of wide field galaxy surveys, both spectroscopic and photometric, we expect to achieve unprecedented constraints on the expansion history of the universe and the growth of structure. Maximizing the flow of information from these rich datasets to constraints on our physical models requires accurate characterization of systematic uncertainties. First, we present a method for estimation of covariance matrices of galaxy clustering measurements with spectroscopic surveys. We show that our method enables us to generate accurate galaxy mocks needed for BAO and RSD analyses on nonlinear scales. Then, we present the main challenges in extracting cosmological information from lensing measurements of deep imaging surveys. We show that employing novel techniques in estimation of the point spread function can keep this major systematic under control. Finally, we discuss various approaches for improvement of the photometric redshifts for the imaging surveys. We demonstrate how the precision and accuracy of photometric redshifts can be greatly enhanced if we take advantage of combining different datasets.

  62. Physics Colloquium

    "And yet they attract: superconductivity in the presence of strong repulsion"

    Presented by Andre-Marie Tremblay, University of Sherbrooke, Quebec, Canada

    Tuesday, January 17, 2017, 3:30 pm
    Large Seminar Room, Bldg. 510

    Hosted by: ''Wenhu Xu''

    Band theory and the BCS theory of superconductivity are two pillars of the quantum theory of solids. High-temperature superconductors belong to a family of materials where both of these, band theory and BCS, fail. Layered organic materials of the BEDT family are another example of materials that are hard to understand within conventional approaches. The root cause of these failures can be traced to strong electronic repulsion. I will start from the simplest model that takes into account the competition between kinetic and potential energy, the Hubbard model. I will show how cluster generalizations of dynamical mean-field theory for this model shed light on these problems. The interaction-induced metal-insulator transition (Mott transition) can serve as an organizing principle for the phase diagrams.

  63. Nuclear Theory/RIKEN Seminar

    "Going with the flow: solving sign problems in complex space"

    Presented by Paulo Bedaque, University of Maryland

    Friday, January 13, 2017, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: ''Heikki Mantysaari''

    We discuss a new approach to solve the sign problem arising in the Monte Carlo evaluation of path integrals. It is based on deforming the contour of integration into complex space. We will argue that for conceptual and numeric reasons it may be advantageous not to use the steepest descent manifolds (thimbles). We will discuss a variety of algorithms and their application to field theories with a fermionic sign problem and to quantum mechanical models, including real time dynamics.

  64. Condensed-Matter Physics & Materials Science Seminar

    "Transient Dynamics of Strongly Correlated Electrons After Sudden Excitations"

    Presented by Marco Schiro, Institut de Physique Theorique (IPhT), CEA, Saclay, France

    Friday, January 13, 2017, 1:30 pm
    Seminar Room 2nd Floor Bldg 734

    Hosted by: 'Robert Konik'

    The development of pump-probe spectroscopies with femtosecond time resolution, which allows to track the dynamics of electronic degrees of freedom in solids under optical excitations, opens up a new window to understand strongly correlated materials and offers the intriguing possibility of controlling their properties with light, on ultra-fast time scales. Triggered by these advances, the interest around time dependent phenomena in quantum many body systems has recently substantially grown. In this talk will review recent progress in understanding transient dynamics of electrons in correlated metals, Mott Insulators and superconductors. I will show that quite generically these systems display very sharp dynamical transitions as a function of the external perturbation, in correspondence of which the lattice response and the sensitivity to density inhomogeneities can be greatly enhanced.

  65. Particle Physics Seminar

    "The muon g-2 experiment at Fermilab"

    Presented by Vladimir Tishchenko, BNL

    Friday, January 13, 2017, 10 am
    Small Seminar Room, Bldg. 510

    Hosted by: 'Xin Qian'

    There exists a long-standing, intriguing, discrepancy between the BNL E821 measurement and the Standard Model (SM) prediction for the muon anomalous magnetic moment, $a_{\mu} \equiv (g-2)/2$, at the level of about three standard deviations ($3\sigma$). To test this discrepancy, a new muon $(g-2)$ experiment E989 at Fermilab will improve the experimental uncertainty by a factor of four. Providing that the central value remains unchanged, the new measurement would result into more than $5\sigma$ ``discovery-level'' deviation from the SM. The experiment at Fermilab will employ the original BNL storage ring with an intense new muon source and state-of-the-art detector systems. I will review the current status of the design of new components and upgrades that are required to achieve the challenging precision goal of the experiment.

  66. Particle Physics Seminar

    "Analysis Methods in Neutrino Experiments"

    Presented by Dr. Thomas Junk, Fermilab

    Thursday, January 12, 2017, 3 pm
    Small Seminar Room, Bldg. 510

    Hosted by: ''Xin Qian''

    Current and planned neutrino experiments address fundamental questions in the neutrino, astrophysical, nuclear, and new physics sectors with ambitious, large-scale facilities and detectors. Maximizing the sensitivity and physics reach of these experiments is the guiding principle for the design of the apparatus as well as the analysis techniques applied to infer results from the data. These experiments, however, pose challenges in this process: the data frequently have ambiguities and some quantities are not measurable, such as the momenta of outgoing neutrinos or recoiling nuclei. Detectors with high density and spatial granularity provide a large number of measured values for each event that must be sifted through to obtain even basic reconstructed quantities. The impact of the values of model parameters on the predicted event rates is not linear but is frequently oscillatory. Systematic uncertainties must be highly constrained in order to tease out small effects. To address these challenges, a variety of sophisticated techniques have been adapted from earlier experiments, such as well-established statistical methods and analysis techniques. New, innovative tools developed in other fields, such as deep-learning methods, are being applied to neutrino experiments. I will give a survey of some of the interesting developments being applied and planned for the future.

  67. RIKEN Lunch Seminar

    "Plasmon mass scale and linearized gauge field fluctuations in classical Yang-Mills theory"

    Presented by Jarkko Peuron, University of Jyvaskyla

    Thursday, January 12, 2017, 12:30 pm
    Building 510, Room 2-160

    Hosted by: 'Heikki Mantysaari'

    In this talk I discuss the determination of plasmon mass in classical real-time Yang-Mills theory on a lattice in 3 spatial dimensions. I compare 3 different methods to determine the plasmon mass : a hard thermal loop expression in terms of the particle distribution, an effective dispersion relation constructed from fields and their time derivatives, and by measuring oscillations between electric and magnetic field modes after artificially introducing a homogeneous color electric field. Due to plasma instabilities, small quantum fluctuations on top of the classical background may significantly affect the dynamics of the system. I argue for the need for a numerical calculation of a system of classical gauge fields and small linearized fluctuations in a way that keeps the separation between the two manifest. I derive and test an explicit algorithm to solve these equations on the lattice, maintaining gauge invariance and Gauss's law.

  68. HET Seminar

    "Search For Dark matter In Terms of Dark Bound States"

    Presented by Yue Zhang, Northwestern

    Wednesday, January 11, 2017, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: ''Amarjit Soni''

  69. Physics Colloquium

    "Searches for Decays of Heavy Higgs Boson to Gauge Bosons with the ATLAS detector"

    Presented by Scott Snyder, BNL

    Tuesday, January 10, 2017, 3:30 pm
    Large Seminar Room, Bldg. 510

    Hosted by: 'Andrei Nomerotski'

    Following the discovery of the Higgs boson in 2012, the ATLAS experiment at the LHC has been searching for signs of new physics related to the Higgs boson. One promising area is the seach for new, heavy Higgs-like scalars decaying to a pair of vector gauge bosons. This talk will summarize recent ATLAS searches for a heavy scalar decaying to two Z bosons, using the sqrt(s)=13 TeV data from Run 2

  70. Nuclear Physics Seminar

    "Phenomenology of Wigner distributions"

    Presented by Andrei Belitsky, Arizona State University

    Tuesday, January 10, 2017, 11 am
    Small Seminar Room, Bldg. 510

    Hosted by: ''Oleg Eyser''

    We overview physics of nucleon phase space distributions and diverse high energy processes where they are accessible with current and future machines.

  71. Nuclear Theory/RIKEN Seminar

    "Prompt atmospheric neutrino flux and forward charm production in proton-nucleus collisions"

    Presented by Anna Stasto, Penn State

    Friday, January 6, 2017, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: ''Heikki Mantysaari''

    The discoveries of the extraterrestrial neutrino flux by IceCube renewed interest in the precise evaluation of the background neutrinos which are produced in the atmosphere due the cosmic ray interactions. One of the most relevant processes at high energies is the charm and beauty production in proton-nucleus collisions which needs to be evaluated at very high energies where small x effects may become important. I will discuss a recent calculation of the forward charm production in pp and pA, and compare results from different models which include small x effects due to resummation and saturation. Comparison with the LHC data will be presented and nuclear effects on light nuclei will also be discussed. Finally, I will show the resulting prompt neutrino flux and its uncertainties and discuss the potential improvements.

  72. Center for Functional Nanomaterials Seminar

    "DNA Assembled Nanoparticle Clusters for Nanomedicine"

    Presented by Liangcan He, University of Colorado Boulder

    Monday, December 19, 2016, 1:30 pm
    CFN, Bldg 735, Conference Room A, 1st Floor

    Hosted by: ''Oleg Gang''

    In this talk, I will describe the use of nucleic acids to assemble different types of nanocrystals for theranostic applications. In the first part, I will talk about our work on coupling gold nanoparticles (AuNPs) and gold nanostars (AuNSs) to silica-coated upconverting nanoparticles (UCNPs) and their effect on photoluminescence. The experimental and simulation studies showed that the orientation and distance of the UCNP with respect to the core and arms of the gold nanostructures played a significant role in photoluminescence. Also, the AuNS-UCNP assemblies were able to cause rapid gains in temperature of the surrounding medium enabling their potential use as a multi-therapy agent. Then, photodynamic therapy (PDT) was induced by embedding singlet oxygen photosensitizers in mesoporous silica shells on the UCNPs. It showed the Au-UCNP clusters with optimized plasmon resonance and compositions could provide both in vitro imaging contrast and combined cell killing through simultaneous photothermal (PTT) and photodynamic (PDT) therapy under NIR light photoexcitation. In addition to the Au-UCNP studies, I will also describe our recent efforts on building well-defined core-satellite porphyrinic metal-organic framework (MOF)-UCNP assemblies by DNA templating. In this work, UCNPs were well organized around a centrally located MOF nanoparticles. Under NIR irradiation, the emitted light from the assembled UCNPs excited each core MOF NP to produce singlet oxygen (1O2) at significantly greater amounts than that produced from simply mixing UCNPs and MOF NPs, demonstrating their promise as theranostic photodynamic agents. In the second part, I will briefly introduce my graduate work in the Ph.D. study on noble metal nanoparticles-MOFs hybrid materials for SERS detecting and multifunctional drug delivery vehicles.

  73. Nuclear Theory/RIKEN Seminar

    "Proton fluctuations and multi-particle rapidity correlations"

    Presented by Kevin Dusling, PRL

    Friday, December 16, 2016, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: 'Heikki Mantysaari'

    The effect of intrinsic fluctuations of the proton saturation momentum scale on event-by-event rapidity distributions in small systems is explored. Saturation scale fluctuations generate an asymmetry in the single particle rapidity distribution in each event resulting in genuine n-particle correlations. We introduce a color domain model that naturally explains the centrality dependence of the two-particle rapidity correlations recently measured by ATLAS, constraining the probability distribution of saturation scale fluctuations in the proton. Predictions for n=4, 6 and 8 particle rapidity correlations find that the four- and eight-particle cumulant change sign at intermediate multiplicities, a signature which could be tested experimentally.

  74. HET Lunch Discussions

    "The ttbar resonance lineshape using NLO EFT"

    Presented by Cen Zhang, BNL

    Friday, December 16, 2016, 12:15 pm
    Building 510, Room 2-160

    Hosted by: 'Christoph Lehner'

  75. HET/RIKEN Seminar

    "The Fate of Axion Stars"

    Presented by Hong Zhang, Ohio State University

    Wednesday, December 14, 2016, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: ''Pier Paolo Giardino''

  76. Nuclear Physics Seminar

    "Evidence for light-by-light scattering in 5.02 TeV Pb+Pb collisions with the ATLAS detector at the LHC"

    Presented by Mateusz Dyndal, DESY

    Tuesday, December 13, 2016, 11 am
    Small Seminar Room, Bldg. 510

    Hosted by: 'Peter Steinberg'

    I report evidence for light-by-light scattering, using 480ub^−1 of 5.02 TeV Pb+Pb collision recorded by the ATLAS experiment at the LHC. After background data at subtraction and analysis corrections, the cross section of gamma gamma-> gamma gamma process for photon transverse momentum, E_T > 3 GeV, photon pseudorapidity, |η| < 2.4, diphoton invariant mass greater than 6 GeV, diphoton transverse momentum lower than 2 GeV and diphoton aco- planarity below 0.01, has been measured to be 70 ± 20 (stat.) ± 17 (syst.) nb, which is in agreement with the SM prediction of 49 ± 10 nb.

  77. Nuclear Theory/RIKEN Seminar

    "Hydrodynamics, the gradient expansion and transient modes"

    Presented by Michal Heller, Perimeter Institute

    Friday, December 9, 2016, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: ''Heikki Mantysaari''

    I will discuss recent developments at the interplay between hydrodynamic gradient expansion and transient modes in expanding plasma.

  78. HET Lunch Discussions

    "Weak decays beyond NLO III"

    Presented by Mattia Bruno, BNL

    Friday, December 9, 2016, 12:15 pm
    Building 510, Room 2-95

    Hosted by: 'Christoph Lehner'

  79. RIKEN Lunch Seminar

    "Analytic Results for Color Glass In Space-Time Coordinates"

    Presented by Rainer Fries, Texas A&M University

    Thursday, December 8, 2016, 12:30 pm
    Building 510, Room 2-160

    Hosted by: ''Heikki Mantysaari''

    I will start by reviewing some previous results for the McLerran-Venugopalan model for nuclear collisions solved analytically in space-time coordinates. I will then discuss some recent work on initial angular momentum in the resulting Yang-Mills system, which leads to an interesting picture of gluon flow in the event plane. I will also describe further evolution of these results in fluid dynamics. Time permitting I will touch on ongoing efforts to construct an event generator based on analytic solutions.

  80. Joint: YITP/HET

    "Enhancing searches for beyond the Standard Model physics at the LHC"

    Presented by Michele Papucci, Berkeley

    Wednesday, December 7, 2016, 2:30 pm
    YITP Seminar Room

    In this talk I'll present recent work on improving the capabilities for looking for new physics at the LHC, both for exotics BSM signals (hidden valleys) and for Dark Matter. I will also discuss soon to be publicly available tools for connecting LHC results with theoretical models.

  81. Nuclear Theory/RIKEN Seminar

    "Squeeze Out"

    Presented by Ron Longacre, BNL

    Wednesday, December 7, 2016, 11 am
    Small Seminar Room, Bldg. 510

    Hosted by: '''Heikki Mantysaari'''

    Squeeze out happen when the expanding central fireball flows around a large surface flux tube in a central Au-Au collision at RHIC. We model such an effect in a flux tube model. Two particle correlations with respect to the $v_2$ axis formed by the soft fireball particles flowing around this large flux tube is a way of measuring the effect.

  82. Nuclear Physics Seminar

    "Quarkonium and Open Heavy Flavor productions at collider energies in Small-x formalism"

    Presented by Kazuhiro Watanabe, Old Dominion University/Jefferson Lab

    Tuesday, December 6, 2016, 11 am
    Small Seminar Room, Bldg. 510

    Hosted by: 'Oleg Eyser'

    Heavy quark pair production in high energy proton-nucleus (pA) collisions provides valuable information on the gluon saturation dynamics at small-x of a heavy nucleus. Nowadays, large amounts of data of quarkonium, open heavy flavor, and decay lepton accumulated by RHIC and LHC enable us to examine the calculations in Small-x formalism or Color Glass Condensate (CGC). Essentially, the calculations of heavy quark pair production have been based on the Small-x/CGC framework at leading order (LO) with the running coupling Balitsky-Kovchegov equation (rcBK) which includes a subset of next-to-leading order (NLO) correction. A main difference between pp and pA collisions is the choice of the initial saturation scale in the rcBK equation. The recent theoretical computations have gradually clarified the gluon saturation effect in pA collision by comparing with data on the transverse momentum spectrums and the nuclear modification factors measured at RHIC and LHC. In this talk, we will review the recent studies of heavy quark pair production in the Small-x/CGC framework and discuss the relevant topical issues. Furthermore, we will discuss the Sudakov implementation in Small-x formalism which has received attention in recent years. I will show that the Sudakov effect on top of the saturation effect is indeed indispensable for Upsilon production.

  83. Nuclear Theory/RIKEN Seminar

    "Renormalization-group flow of the effective action of cosmological large-scale structures"

    Presented by Stefan Flörchinger, Heidelberg

    Friday, December 2, 2016, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: '''Heikki Mantysaari'''

    The large scale structure of the universe forms a particular type of fluid which is governed by the properties of dark matter. I discuss how one can derive renormalization group equations for the effective action that describes the statistical properties of this fluid. Taking into account in particular effective viscosity and sound velocity terms leads to an improved framework to determine density and velocity power spectra.

  84. CFN Colloquium

    "The emergence of hybrid-perovskites for low-cost, high-efficiency optoelectric devices"

    Presented by Aditya D. Mohite, Los Alamos National Laboratory

    Thursday, December 1, 2016, 4 pm
    CFN, Bldg 735, Seminar Room, 2nd Floor

    Hosted by: ''''Matthew Sfeir''''

    Hybrid (inorganic-­-organic) perovskites have demonstrated an extraordinary potential for clean  sustainable  energy  technologies  and  low-­-cost  optoelectronic  devices  such  as  solar  cells; light emitting diodes, detectors, sensors, ionic conductors etc. In spite of the unprecedented  progress  in  the  past  six  years,  one  of  the  key  challenges  that  exist  in  the  field today is the large degree of processing dependent variability in the structural and physical  properties.  This  has  limited  the  access  to  the  intrinsic  properties  of  hybrid  perovskites and led to to multiple interpretations of experimental data. In addition to this, the stability and reliability of devices has also been strongly affected and remains an open question,  which  might  determine  the  fate  of  this  remarkable  material  despite  excellent  properties. In this talk, I will describe our recently discovered approach for thin-­-film crystal  growth  as  a  general  strategy  for  growing  highly  crystalline,  bulk-­-like  thin-­-films  of  both three-­-dimensional (3D) and layered two-­-dimensional (2D) hybrid perovskites that overcomes the above issues by allowing access to the intrinsic charge and energy transport processes  within  the  perovskite  thin-­-films  and  results  in  reproducible  and  stable  high  performance optoelectronic devices.

  85. Condensed-Matter Physics & Materials Science Seminar

    "Complexity in Spin-Frustrated Rock-Salt Manganites"

    Presented by Alexandros Lappas, Institute of Electronic Structure and Laser, Foundation for Research & Technology, Greece

    Thursday, December 1, 2016, 1:30 pm
    ISB Bldg. 734, Conf. Rm. 201 (upstairs)

    Hosted by: 'Emil Bozin'

    Complexity in transition metal oxides is the outcome of simultaneously active electron degrees of freedom (spin-charge-orbital) and their evolution under the restrictions imposed by the geometry of the underlined crystal lattice. Consequently, the materials' response to competing states requires that we assess structural correlations across a wide range of length and time scales. Taking advantage of cutting-edge structural facilities accessed at neutron [1, 2], synchrotron X-ray [3] and electron microscopy [4] labs we address current limitations in understanding the crystallographic structure of layered rock-salt type triangular-lattice manganites of the AMnO2 type (A= Na, Cu). The unexpected coexistence of long- and short-range magnetic correlations [3, 5] due to two major opposing effects (elastic vs. magnetic exchange) of similar magnitude, lead to nearly equivalent, competing structural phases enabling infinitesimal quenched disorder to locally lift the differing degree of inherent frustration in the parent AMnO2 phase. These manganites provide a paradigm of a rarely observed nanoscale inhomogeneity in an insulating spin system, an intriguing complexity of competition due to geometrical frustration. The dramatic impact of topology and site-disorder on frustrated magnetism is further demonstrated by the hydrated variant of the NaMnO2 antiferromagnet, which gives way to a strongly interacting spin-glass state, indicative of the subtle balance of competing processes in multivalent two-dimensional systems [6]. [1] M. Giot et al., Phys. Rev. Lett. 2007, 99, 247211. [2] C. Vecchini et al., Phys. Rev. B 2010, 82, 094404. [3] A. Zorko et al., Nat. Commun. 2014, 5, 3222. [4] A.M. Abakumov et al., Chem. Mater. 2014, 26, 3306. [5] A. Zorko et al., Sci. Rep. 2015, 5, 9272. [6] I. Bakaimi et al., Phys. Rev. B 2016, 93, 184422.

  86. HET/RIKEN Seminars

    "Heavy meson decays to light resonances"

    Presented by Luka Leskovec, University of Arizona

    Wednesday, November 30, 2016, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: ''Mattia Bruno''

    Lattice QCD calculations of electroweak decays with single, strong-interaction-stable hadrons in the initial and final state have recently reached a high level of precision. Many phenomenologically important decays, however, involve hadronic resonances, and their naive analysis on the lattice leads to uncontrolled systematic errors. Recent theoretical developments in the finite-volume treatment of $1 \to 2$ transition matrix elements now enable us to perform rigorous lattice calculations of electroweak decays to light resonances such as the $\rho$. After presenting the Briceno-Hansen-Walker-Loud formalism, I will discuss our numerical implementation for the $D\to\rho \ell \nu$ and $B\to\rho \ell \nu$ decays, where we aim to quantify the effect of the unstable nature of the $\rho$. Our calculations are performed on a gauge ensemble with 2+1 flavors of clover fermions with a pion mass of ~320 MeV and a lattice size of ~3.6 fm.

  87. Physics Colloquium

    "Isolated quantum systems in extreme conditions: From heavy-ion collisions to ultracold quantum gases"

    Presented by Juergen Berges, University of Heidelberg

    Tuesday, November 29, 2016, 3:30 pm
    Large Seminar Room, Bldg. 510

    Hosted by: ''Rob Pisarski''

    Isolated quantum systems in extreme conditions can exhibit characteristic common properties despite dramatic differences in key parameters such as temperature, density, field strength and others. The existence of universal regimes, where even quantitative agreements between seemingly disparate physical systems can be observed, drives a remarkable convergence of research activities across traditional lines of specialization. I will describe the concerted research efforts by the recently established Heidelberg Collaborative Research Center ISOQUANT in collaboration with BNL and discuss recent developments concerning the thermalization dynamics of non-Abelian plasmas and ultracold atoms.

  88. Nuclear Physics Seminar

    "Accessing Gluon Polarization with Di-jets: Present and Future"

    Presented by Brian Page, BNL

    Tuesday, November 29, 2016, 11 am
    Small Seminar Room, Bldg. 510

    Hosted by: 'Oleg Eyser'

    Despite extensive theoretical and experimental effort, a detailed understanding of how the proton spin is built up from the spins and orbital angular momenta of its constituents remains elusive. Polarized fixed-target deep inelastic scattering data has constrained the contribution from quark and anti-quark helicities to be roughly 30% for parton momentum fractions greater than 10^-3, while inclusive jet and $\pi^0$ asymmetry results from the STAR and PHENIX experiments at RHIC have placed strong constraints on the gluon helicity contribution for momentum fractions greater than 0.05. This talk will detail the extension of STAR inclusive jet measurements to correlated di-jet measurements, which better constrain the initial partonic kinematics. Recently released di-jet asymmetry results from STAR will be presented and the status of future measurements will be discussed. Di-jet asymmetry measurements will also play an important role in constraining the gluon helicity contribution to the proton spin at a future Electron-Ion Collider, and the prospects for such measurements will be outlined.

  89. Condensed-Matter Physics & Materials Science Seminar

    "X-ray Photon Correlation Spectroscopy at Large Angles"

    Presented by Mark Sutton, McGill University

    Tuesday, November 22, 2016, 1:30 pm
    ISB Bldg. 734, Conf. Room 201 (upstairs)

    Hosted by: 'Mark Dean'

    Xray photon correlation spectroscopy (XPCS) has proven to be a powerful way to study time correlations in equilibrium systems. The straight forward extension to two-time correlations has also proven very useful. To date, most XPCS work has been done using small-angle x-ray scattering (SAXS). As with conventional x-ray diffraction, the information in disordered Bragg peaks (large angle scattering) often contains more information but it can be harder to interpret. In this talk, I will discuss several results using large angle XPCS which explore some of the complications and the resulting extra information obtained.

  90. Condensed-Matter Physics & Materials Science Seminar

    "Probing the magnetic structure of EuPtIn4 via x-ray resonant magnetic scattering"

    Presented by Jose Renato Mardegan, Deutsche Elektronen-Synchrotron (DESY), Germany

    Tuesday, November 22, 2016, 11 am
    ISB Bldg. 734, Seminar Rm. 201 (upstairs)

    Hosted by: ''Ian Robinson''

    The search for fascinating materials with interesting electronic and magnetic properties has led to an enormous development in diverse areas of condensed matters physics. In particular, the Indium-rich materials containing rare-earth elements can host exotic physical phenomena emerging from the competition and/or cooperation of several physical mechanisms such as the Ruderman-Kittel-Kasuya-Yosida (RKKY) magnetic interaction, heavy fermion (HF) behavior, crystalline electric field (CEF) and Kondo effects[1,2].Since the magnetic ordering and the screening of f-electrons have an important role in the ground state properties of these materials, the magnetic structure determination can be a powerful tool to understand how the moments of the magnetic ions are interacting among each other. In this sense, x-ray resonant magnetic scattering (XRMS) technique was employed to solve the magnetic structure at low temperature of the new intermetallic EuPtIn4 compound. At the resonant energy of the Eu ion (7617 eV – L2 edge), magnetic incommensurate (ICM) reflections with propagation vector type (1/2, 1/2, τ) with τ ~ 0.427 were observed. Temperature and magnetic field dependence performed at the magnetic reflections reveal an AFM coupling with a Néel temperature TN = 13.1 K and a spin flop transition above 3 T, respectively. In addition, we do not observe any magnetic anomalies related to a second phase transition as suggested in the previously reported macroscopic measurements [3,4]. The ICM phase observed at low temperature is due to geometric frustration of the Eu ions in which the RKKY exchange interaction cannot be simultaneously satisfied. Although the EuPtIn4 compound displays similar properties to a heavy fermion compound such as exotic magnetic structure and enhancement of Sommerfeld coefficient, further investigation must be performed in this new series of materials.[1] Z. Fisk, et al., Proc. Natl. Acad. Sci. USA 92, 6663 (1995).[2] P. Coleman, Handb

  91. Nuclear Physics Seminar

    "Chromodynamic Rutherford Scattering?"

    Presented by John Dainton, Cockcroft Insitute, University of Liverpool

    Tuesday, November 22, 2016, 11 am
    Small Seminar Room, Bldg. 510

    Hosted by: ''Oleg Eyser''

    It is asserted that precision measurements of exclusive processes in high-luminosity electron-hadron interactions are the way forward in understanding hadron physics in Nature. Such processes involve the control of more than one scale and thereby enable experimental analysis in terms of phenomenology which can then challenge theoretical calculation in specific ways and on which it will be possible to build a full understanding of chromodynamic mechanism. The presentation is built on initial steps in an on-going analysis of published measurements of exclusive meson production at the HERA ep collider. It already can be seen to indicate that the assertion could well be well justified with precision measurements in the future in a high luminosity electron hadron collider.

  92. Particle Physics Seminar

    "The Short Baseline Neutrino program: laying the groundwork for DUNE"

    Presented by Georgia Karagiorgi, Columbia University

    Tuesday, November 22, 2016, 9:30 am
    Small Seminar Room, Bldg. 510

    Hosted by: '''Xin Qian'''

    The Short Baseline Neutrino (SBN) Program comprises three liquid argon time projection chamber detectors which are planning to study neutrinos from the Booster Neutrino Beamline at Fermilab, at three different locations close to the neutrino production. The trio of detectors will be able to perform precise neutrino cross section measurements, and search for short-baseline neutrino oscillations and other non-standard effects, addressing pressing questions in the field of neutrino oscillations. The SBN detectors also share the same detector technology as the future, O(100) times larger detector that will be employed for the Deep Underground Neutrino Experiment. They therefore provide a testbed for R&D and for demonstrating the liquid argon TPC technology and its scalability. This seminar will highlight selected physics and R&D opportunities with SBN.

  93. Condensed-Matter Physics & Materials Science Seminar

    "Tracking chemical reactions with time-resolved x-ray spectroscopic techniques"

    Presented by Tadese Abebaw Assefa, European XFEL Laboratory, Germany

    Monday, November 21, 2016, 1:30 pm
    ISB Bldg. 734, Conf. Rm. 201 (upstairs)

    Hosted by: ''Ian Robinson''

    Transition metal compounds play a significant role in many chemical and biologically relevant processes. Hereby charge transfer, ligand detachment and attachment processes are fundamental ingredients, which often determine the outcome of a given chemical reaction. We investigated aqueous ferrocyanide ([FeII(CN)6]4-) ions, which undergoes charge transfer and ultrafast ligand dissociation upon irradiation of 266 and 355 nm laser light. Time-resolved (TR) x-ray absorption and emission spectroscopies (XAS and XES) deliver information about structural and electronic changes in real-time implemented to follow the chemical reaction. Synchrotron-based studies are limited with 100ps time resolution enables us to disentangle simultaneous photoproducts formed after 266 nm laser excitation. Furthermore, we investigated the ultrafast ligand dissociation of aqueous ferrocyanide ions upon irradiation of 355 nm laser light at the x-ray Free Electron Laser facility (SACLA, Japan). Based on a comparison of the simulated pre-edge peaks of 1s→3d transition with the experimental data, we concluded that the reaction pathway commences via ligand detachment resulting pentacoordinated intermediate complex ([FeII(CN)5]3-), followed by the formation of the long-lived photoaquated complex ([FeII(CN)5(H2O)]3-). The ligand detachment and attachment process takes 12.43 ± 5.77 ps. TR XES results also reveal spin state change in the intermediate state. Combining these findings we interpret the consecutive steps of ligand exchange mechanism for ferrocyanide ions. Also, we characterise the molecular structure of photoexcited [FeII(terpy)2]2+ molecule via TR Extended X-ray absorption fine structure (EXAFS). The data analysis in energy space used two structural model expansions which are the representations of DFT predicted 5E and 5B2 quintet high spin states. After statistical evaluation of the two models, the 5E high spin state model is in better agreement with experimental data. The ener

  94. Nuclear Theory/RIKEN Seminar

    "Phase structure and dynamics of dense QCD"

    Presented by Armen Sedrakian, Frankfurt

    Friday, November 18, 2016, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: ''''Heikki Mantysaari''''

    In the first part of the talk I will discuss recent computations of the transport coefficients of dense QCD from the Kubo formalism on the basis of a two-flavor model of QCD. The second part of the talk will discuss the properties of compact stars featuring color superconducting phases of dense QCD. This will include modeling of massive compact stars, neutrino cooling of such stars, and possible signatures of a phase transition within the QCD phase diagram in the X-ray data from the young neutron star in Cassiopea A.

  95. HET Lunch Discussions

    "ALPs and the Muon g-2 Discrepancy"

    Presented by William J. Marciano, BNL

    Friday, November 18, 2016, 12:30 pm
    Building 510, Room 2-160

    Hosted by: ''Christoph Lehner''

  96. Particle Physics Seminars- SB/BNL Joint Cosmo Seminar

    "A more precise and accurate route from sky images to cosmological constraints"

    Presented by Gary Bernstein, University of Pennsylvania

    Thursday, November 17, 2016, 3 pm
    Small Seminar Room, Bldg. 510

    Hosted by: ''Anze Slosar''

    Current (e.g. DES) and future (e.g. LSST, Euclid) experiments aim to convert multiband images of the sky into precise constraints on cosmological models, neutrino masses, and modifications of general relativity. This standard path for this inference involves making point estimates of the galaxies' redshifts (from observed colors) and weak gravitational lensing distortions (from observed morphologies), then combining these into various cross-correlations and other summary statistics that are compared to numerical simulations of the Universe. These estimators require a slew of empirical corrections to various biases, and have yet to demonstrate accuracies sufficient to reduce biases below systematic errors. I describe two steps to greatly simplify this process and eliminate the need for simulation-based calibration of estimators: first, a practical means to estimate the joint posterior probability of a galaxies' redshift and line-of-sight lensing; second, a method to sample from the posterior distribution of all mass distributions and cosmologies conditional on the galaxy density and lensing data. The main advantages of the new scheme include improved lensing and photo-z accuracy (to the required part-per-thousand level), recovery of non-Gaussian information that is lost in the usual 2-point summary statistics, and correct propagation of uncertainties (including photo-z uncertainties) into the cosmological inferences.

  97. Nuclear Theory/RIKEN Seminar

    "Quantum-field-theoretical approach to shear and bulk relaxation times"

    Presented by Alina Czajka, McGill

    Thursday, November 17, 2016, 12:30 pm
    Building 510, Room 2-160

    Hosted by: ''Heikki Mantysaari''

    The shear and the bulk relaxation times are important ingredients of the second order hydrodynamics whose success in heavy ion phenomenology is unquestioned. Unlike viscosites themselves, field theoretical calculations of the relaxation times are hard to come by in literature, especially for the bulk relaxation time. In this talk, we report two field-theoretical analyses involving the shear and the bulk relaxation time. First, by carefully examining the analytic structure of the stress-energy tensor response functions, we have been able to derive, for the first time, a Kubo formula involving both the shear and the bulk relaxation times. Second, by evaluating the Kubo formula within the massless scalar theory, we have so far been able to calculate the shear relaxation time in a simple form. We will then show how this calculation can be extended to calculate the bulk relaxation time as well.

  98. Joint YITP/HET Seminar

    "A Predictive Theory for All Required and Measurable CP Violation"

    Presented by Scott Thomas, Rutgers

    Wednesday, November 16, 2016, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: '''Amarjit Soni'''

  99. Physics Colloquium

    "Low-energy Precision Physics and the Role of Lattice QCD"

    Presented by Harmut Wittig, University of Mainz

    Tuesday, November 15, 2016, 3:30 pm
    Large Seminar Room, Bldg. 510

    Hosted by: 'Peter Petreczky'

    The particle content of the Standard Model has been completely established following the discovery of the Higgs boson. While the Standard Model describes all known phenomena in accelerator-based experiments, many important questions are left unanswered. In this talk I describe several attempts to detect signals for physics beyond the Standard Model using precision experiments at low energies. Special attention is given to the anomalous magnetic moment of the muon and the role of lattice QCD in quantifying the hadronic uncertainties in its theoretical prediction.

  100. Nuclear Physics Seminar

    "Is there a low p_T anomaly in the pion momentum spectrum at LHC?"

    Presented by Pasi Huovinen, University of Wroclaw

    Tuesday, November 15, 2016, 11 am
    Small Seminar Room, Bldg. 510

    Hosted by: 'Oleg Kjeld'

    The low p_T part of the pion spectrum measured by the ALICE collaboration has turned out to be very difficult to reproduce using conventional fluid dynamical approaches. In this talk I discuss how the finite width of rho mesons affects the yield of rhos and the distribution of pions originating from rho decays, and how inclusion of the finite width in the description of resonances may help to explain the low p_T pion data.

  101. Particle Physics Seminar: SB/BNL Joint Cosmo Seminar

    "Revealing CII Emission with LSS Cross-correlations"

    Presented by Anthony Pullen, NYU

    Thursday, November 10, 2016, 3 pm
    Small Seminar Room, Bldg. 510

    Hosted by: '''''Anze Slosar'''''

    The CII emission line tends to be the brightest line in star-forming galaxies, making it an ideal tracer of large-scale structure. Through the method of intensity mapping, astronomers hope to map CII emission at cosmological redshifts and large volumes, making CII and unprecedented probe of cosmology and reionization. However, the various models of the expected CII emission are highly uncertain by orders of magnitude, limiting our ability to predict how well potential CII surveys could probe large-scale structure. In this talk, I will present our measurement of excess emission from large scales at redshift z=2.5 potentially attributable to CII emission. This excess emission was measured by cross-correlating the 545 GHz broad-band microwave map from the Planck satellite and high-redshift quasars from the Sloan Digital Sky Survey. I will also discuss future opportunities with CII intensity mapping.

  102. RIKEN Lunch Seminar

    "An overview of lattice field theory applications to dark matter searches"

    Presented by Enrico Rinaldi, RBRC

    Thursday, November 10, 2016, 12:30 pm
    Building 510, Room 2-160

    Hosted by: ''Hiroshi Oki''

  103. Environmental & Climate Sciences Department Seminar

    "Observational constraints on mixed-phase clouds imply higher climate sensitivity"

    Presented by Ivy Tan, Yale Univ.

    Thursday, November 10, 2016, 11 am
    Conference Room Bldg 815E

    Hosted by: 'Robert McGraw'

    Mixed-phase clouds are comprised of both liquid droplets and ice crystals. For a given total water content, mixed-phase clouds with higher liquid water contents are optically thicker and therefore more reflective to sunlight compared to those with higher ice water contents. This is due to the fact that liquid droplets tend to be smaller in size and more abundant than ice crystals in Earth's atmosphere. Given the ubiquity of mixed-phase clouds, the ratio of liquid to ice in these clouds is expected to be important for Earth's radiation budget. We determine the climatic impact of thermodynamic phase partitioning in mixed-phase clouds by using five pairs of simulations run with CAM5/CESM. Of the five pairs of simulations, the thermodynamic phase partitioning of two of the simulations were constrained to better agree with observations from CALIPSO. The other three pairs of simulations include a control simulation, as well as an upper and lower bound simulation with maximally high and low amounts of mixed-phase cloud liquid fractions. An analysis of the simulations shows that a negative "cloud phase feedback" that occurs due to the repartitioning of cloud droplets and ice crystals under global warming is weakened when mixed-phase clouds initially contain a higher amount of liquid. Simulations that exhibited weaker cloud phase feedbacks also had higher climate sensitivities. The results suggest that an unrealistically strong cloud phase feedback leading to lower climate sensitivities may be lurking in the many climate models that underestimate mixed-phase cloud liquid fractions compared to observations.

  104. Particle Physics Seminar

    "An improved ultracold neutron bottle for measuring the neutron lifetime"

    Presented by Dr. E. Adamek

    Thursday, November 10, 2016, 10 am
    Small Seminar Room, Bldg. 510

    Hosted by: '''Xin Qian'''

    The neutron beta decay lifetime is an important parameter in theories of weak interaction and big bang nucleosynthesis. To this end, many experiments over the past several decades have sought to improve the precision of this value. Ultracold neutrons, or UCN, are neutrons with extremely low energies which can be contained by material walls; these have provided us with a useful tool in measuring the neutron lifetime. The most recent set of experiments have demonstrated a 6sigma discrepancy between two lifetime values, each obtained using a different method of measurement. The UCNtau experiment at Los Alamos Neutron Science Center, is a bottling experiment which is designed to hold UCN within a 600 liter magnet-lined bowl to store the neutrons through magnetogravitational trapping. The open topped nature of the storage vessel allows for detectors to be lowered into the UCN volume to take in-situ measurement of the surviving UCN after varying storage times. This talk will cover newly presented results from the most recent UCNtau experiment data.

  105. HET/RIKEN Seminars

    "When the Higgs meets the Top"

    Presented by Chung Kao, University of Oklahoma

    Wednesday, November 9, 2016, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: ''Pier Paolo Giardino''

  106. Particle Physics Seminar

    "TBA"

    Presented by Jo Bovy

    Wednesday, November 9, 2016, 1:30 pm
    Stony Brook University

    Hosted by: 'Neelima Sehgal'

  107. Physics Colloquium

    "Skyrmions and Nuclei"

    Presented by Nick Manton

    Tuesday, November 8, 2016, 3:30 pm
    Large Seminar Room, Bldg. 510

    Hosted by: 'Robert Pisarski'

    Nuclear forces are mediated by pions. As pions are light compared to nucleons and other mesons, they are treated as approximate Goldstone bosons in an effective field theory (EFT) with spontaneously broken SO(4) chiral symmetry. Generically, the nonlinear field equations of EFT have topological soliton solutions called Skyrmions, which we identify as the intrinsic structures of nucleons or larger nuclei. The quantum states of the unit-winding, spherical Skyrmion represent protons and neutrons with spin half. Skyrmions of many higher winding numbers are also known, having beautiful symmetries, and sometimes showing alpha-particle or other clustering. The classical solutions have definite location, orientation, and pion field orientation, so we quantize the collective coordinates to obtain states with definite momentum, spin and isospin. A Skyrmion's symmetry restricts its allowed spin/isospin combinations (Finkelstein—Rubinstein constraints). The recent inclusion of vibrational degrees of freedom has helped to create a reasonable model for Oxygen-16 and its excited states.

  108. Nuclear Physics & RIKEN Theory Seminar

    "Glue spin from lattice QCD"

    Presented by Yi-Bo Yang, University of Kentucky

    Friday, November 4, 2016, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: '''Heikki Mantysaari'''

    I will present the result of the glue spin in proton from the lattice QCD simulation, and also the renormalization and matching issues. The lattice calculation is carried out with valence overlap fermions on 2+1 flavor DWF gauge configurations on four lattice spacings and four volumes including an ensemble with physical values for the quark masses. The glue spin $S_G$ in the $\overline{\text{MS}}$ scheme is obtained with the 1-loop perturbative matching. I will also discuss the generic strategy and possible difficulties of calculating the glue helicity on the lattice, from the large momentum effective theory to the lattice simulations.

  109. HET Lunch Discussions

    "Perturbative Unitarity at NLO in the 2HDM, and Bottom-Quark Forward-Central Asymmetry at LHCb"

    Presented by Christopher Murphy, BNL

    Friday, November 4, 2016, 12:15 pm
    Building 510, Room 2-160

    Hosted by: ''Christoph Lehner''

  110. Condensed-Matter Physics & Materials Science Seminar

    "Surface X-ray Diffraction for Operando Characterization of Chemical Reactions on Surfaces""

    Presented by Roberto Felici, Istituto SPIN - CNR, Italy

    Friday, November 4, 2016, 11 am
    ISB Bldg. 734, Sem. Rm. 201 (upstairs)

    Hosted by: ''''Ian Robinson''''

    X-rays are an ideal probe for studying structural properties of matter and, thanks to the brilliance of synchrotron sources, they are also employed to determine the atomic structure and morphology of surfaces and interfaces. Surface x-ray diffraction has been originally developed to determine the static structure of surfaces. However with the development of x-ray sources, detectors and analysis tools it is now possible to characterise in detail processes which occur at surfaces. Aim of this talk is to present recent results obtained at the id03 surface diffraction beamline of the ESRF dealing with the in-situ characterization of the structure and morphology of a catalyst during a surface reaction. Examples will deal with heterogenous catalytic oxidation of CO on single crystal surfaces /1,2/ and supported nanoparticles /3/ References 1 R. van Rijn et al., Phys. Chem. Chem. Phys. 13 (2011) 13167 2 B.L. Hendriksen et al., Nat. Chem. 2 (2010) 730 3 O. Balmes, et al., Phys. Chem.Chem. Phys. 14 (2012) 4796

  111. RIKEN Lunch Seminar

    "Form Invariance, Topological Fluctuations and Mass Gap of Yang-Mills Theory"

    Presented by Yachao Qian, Stony Brook University

    Thursday, November 3, 2016, 12:30 pm
    Building 510, Room 2-160

    Hosted by: ''Hiromichi Nishimura''

    We study the quantum Yang-Mills theory in the presence of topologically nontrivial backgrounds. The topologically stable gauge fields are constrained by the form invariance condition and the topological properties. Obeying these constraints, the known classical solutions to the Yang-Mills equation in the 3- and 4-dimensional Euclidean spaces are recovered, and the other allowed configurations form the nontrivial topological fluctuations at quantum level. Together, they constitute the background configurations, upon which the quantum Yang-Mills theory can be constructed. We demonstrate that the theory mimics the Higgs mechanism in a certain limit and develops a mass gap at semi-classical level on a flat space with finite size or on a sphere.

  112. HET/RIKEN Seminars

    "Neutrinoless double beta decay from lattice QCD"

    Presented by Amy Nicholson, UC Berkeley

    Wednesday, November 2, 2016, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: ''Mattia Bruno''

  113. Nuclear Physics Seminar

    "Photon-tagged jet production in 5.02 TeV Pb+Pb and pp"

    Presented by Peter Steinberg, BNL

    Tuesday, November 1, 2016, 11 am
    Small Seminar Room, Bldg. 510

    Hosted by: ''Jia Jiangyong''

    Nuclear collisions which produce a high transverse momentum (p_T) prompt photon offer a useful way to study the dynamics of the hot, dense medium produced in these events. Because photons do not carry color charge, they are unaffected by the hot, dense medium. Thus, the outgoing photon serves as a tag of the initial parton flavors, and measures the initial parton pT before they are quenched by their passage through the medium In 2015, ATLAS sampled 0.49 nb-1 and 26 pb-1 of Pb+Pb and pp data at 5.02 TeV, respectively, with a high-level photon trigger that selects p_T>25 GeV photons with high efficiency. The larger prompt photon cross-section and integrated luminosity with respect to 2.76 TeV data allow for new, differential studies of photon-jet correlations. In this talk, ATLAS results on photon-jet azimuthal and pT balance will be presented using pT > 60 GeV photons and R=0.4, pT > 30 GeV jets. Double-differential distributions of the jet-to-photon p_T ratio, x_Jg, and of the azimuthal difference, $\Delta\phi$, will be presented as a function of photon p_T and event centrality.

  114. Nuclear Theory/RIKEN Seminar

    "Perturbative QCD and beyond: Bose-Eitstein correlation and $v_n$ at any n"

    Presented by Genya Levin, Tel Aviv University

    Friday, October 28, 2016, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: ''Heikki Mantysaari''

  115. C-AD Accelerator Physics Seminar

    "The REDTOP Experiment: Rare Eta Decays with a TPC for Optical Photons"

    Presented by Dr. Corrado Gatto, FNAL and INFN

    Friday, October 28, 2016, 10 am
    Large Conference Room Bldg. 911B

    Hosted by: '''Wolfram Fischer'''

    The eta meson is almost unique in the particle universe since it is a Goldstone boson and the dynamics of its decay are strongly constrained. Because the eta has no charge, decays that violate conservation laws can occur without interfering with a corresponding current. The integrated eta meson samples collected in earlier experiments have been less than 1e8 events, limiting considerably the search for such rare decays. A new experiment, REDTOP, is being proposed at the proton booster of Fermilab with the intent of collecting more than 1e12 triggers/year for studies of rare eta decays. Such statistics are sufficient for investigating several symmetry violations, and for searches for new particles beyond the Standard Model. The physics program, the accelerator systems and the detector for REDTOP will be discussed during the seminar.

  116. BWIS Sponsored Lecture

    "Picturing Physics: How Topology Helps Untangle the Puzzle of the Shapes of Things"

    Moira Chas, Stony Brook University

    Thursday, October 27, 2016, 4:30 pm
    Hamilton Seminar Room, Bldg. 555

  117. Condensed-Matter Physics & Materials Science Seminar

    "Driven Dirac Materials"

    Presented by Alexander Balatsky, Los Alamos National Laboratory

    Thursday, October 27, 2016, 1:30 pm
    Bldg. 734, ISB Seminar Rm. 201 (upstairs)

    Hosted by: 'Robert Konik'

    Dirac Materials exhibit nodes in the spectra that result in the strong energy dependence of the Density of States (DOS). Collective many body instabilities in Dirac Materials are controlled by the dimensionless DOS. Hence the driven and nonequilibrium Dirac Materials offer a platform for investigation of collective instabilities of Dirac nodes via controlled tuning of the coupling constants with drive. I will present the results of investigation of the many body instabilities, like excitonic instabilities, in driven Dirac Materials. Recent optical pump experiments are consistent with the creation of long lived states away from equilibrium in Dirac Materials.

  118. RIKEN Lunch Seminar

    "Hybrid approach to relativistic heavy-ion collisions at the RHIC BES energies"

    Presented by Chun Shen, BNL

    Thursday, October 27, 2016, 12:30 pm
    Building 510, Room 2-160

    Hosted by: '''Hiroshi Oki'''

    Using a hybrid (viscous hydrodynamics + hadronic cascade) framework, we model the bulk dynamics of relativistic heavy-ion collisions at the RHIC BES collision energies, including the effects from non-zero net baryon current and its dissipative diffusion during the evolution. The framework is in full 3+1 dimension which allows us to study the non-trivial longitudinal structure and dynamics of the collision systems, for example, the baryon stopping/transport. The collision energy dependence of hadronic chemistry, identified particle spectra, anisotropic flows, and HBT radii is studied from 200 GeV to 19.6 GeV. Effects of breaking boost-invariance, net-baryon current, and its related diffusion on hadronic observables will be addressed. Finally, flow prediction for recent d+Au collisions at the BES energies will be presented within the same framework.

  119. HET/RIKEN Seminars

    "Collider signatures of flavorful Higgs bosons"

    Presented by Stefania Gori, University of Cincinnati

    Wednesday, October 26, 2016, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: ''Pier Paolo Giardino''

  120. Special Nuclear Theory/RIKEN seminar

    "A new relativistic viscous hydrodynamics code for high-energy heavy-ion collisions"

    Presented by Chihi Nonaka, Nagoya University, Japan

    Wednesday, October 26, 2016, 11 am
    Small Seminar Room, Bldg. 510

    Hosted by: ''Chun Shen''

    Relativistic hydrodynamic simulations play a key role in exploring the QGP bulk property and the QCD phase transition from analyses of high-energy heavy-ion collisions at RHIC and LHC. From the intensive study based on relativistic viscous hydrodynamic models with event-by-event initial fluctuations, we can extract detailed information of the bulk feature of the QGP such as transport coefficients and the QCD equations of states. In the quantitative analyses of the QGP property, high-precision numerical treatment on the hydrodynamic calculation is important. Recently, we developed a new 3+1 dimensional relativistic viscous hydrodynamics code in Cartesian coordinates. In the algorithm, we use a Riemann solver based on the two-shock approximation which is stable under existence of large shock waves. We extend the algorithm in Cartesian coordinates to that in Milne coordinates so that we can efficiently apply it to the analyses of relativistic heavy-ion collisions. We check the correctness of the numerical algorithm by comparing numerical calculations and analytical solutions in various problems for ideal and viscous fluids. The new numerical scheme is stable even with small numerical viscosity, which is very important to discuss the physical viscosities at RHIC and LHC.

  121. Physics Colloquium

    "From Stars to Nuclei and Back: Our Cosmic Origin and the Exascale Challenge to Find It"

    Presented by Tony Mezzacappa, University of Tennessee

    Tuesday, October 25, 2016, 3:30 pm
    Large Seminar Room, Bldg. 510

    Hosted by: 'Peter Petreczky'

    We learn in elementary school that the elements in the Periodic Table are the building blocks of our world, including our very bodies. But from where do the elements come? This is among the most basic questions we can ask, yet the precise answer remains elusive. We witness the cycle of life in our daily lives, everywhere on Earth. This is no less true in the Universe. With the exception of the lightest elements such as hydrogen and helium, elements are made in stars. As stars evolve and die, these elements pepper the interstellar medium, from which new stars, and planets, – in particular, our solar system – form. We understand the essential elements of this cycle – from stellar birth, life, and death, to the formation of the elements, to the formation of new stars and planets including those elements, to ultimately the origin of our solar system and life on Earth given those elements. But pieces of the puzzle are missing. We do not yet understand how certain stars that are factories for many of the elements, die, nor do we know the precise origin of half the elements heavier than iron, although we have narrowed down the list of possible sites. Today's colloquium will focus on the death of massive stars in catastrophic explosions known as core collapse supernovae. Such supernovae provide the lion's share of the elements between oxygen and iron, and are considered a potential site for the origin of half the elements heavier than iron. Arguably, they are the single most important source of elements in the Universe. Such supernovae present us with a general relativistic, radiation magneto-hydrodynamic – i.e., a multi-physics – environment to model. Further richness and complexity is added by the fact that the macroscopic evolution of such a system is governed in no small part by the high-density, neutron-rich, nuclear matter at the core of the supernova and by the microscopic interaction of radiation in the form of neutrinos with th

  122. Nuclear Physics Seminar

    "Recent Experimental Results on QCD Factorization Breaking of Nonperturbative Functions"

    Presented by Joe Osborn

    Tuesday, October 25, 2016, 11 am
    Small Seminar Room, Bldg. 510

    Hosted by: 'Jin Huang'

    In the last two decades the study of nucleon structure has shifted from a one-dimensional picture to exploring the dynamic three-dimensional structure of partons within the nucleon. In the transverse-momentum-dependent framework, nonperturbative parton distribution functions (PDFs) and fragmentation functions (FFs) explicitly carry dependence on partonic transverse momentum rather than only the collinear momentum of the parton with respect to the hadron or produced hadron with respect to the fragmenting parton. The recent interest in the transverse structure of the nucleon has largely been motivated by the novel phenomenological consequences that have been predicted for transverse-momentum-dependent nonperturbative functions. Contrary to the collinear framework, certain transverse-momentum-dependent PDFs are predicted to be process dependent. Additionally, factorization breaking has been predicted in hadronic collisions where a final-state hadron is measured and the observable is sensitive to nonperturbative transverse momentum. This prediction has the interesting quantum mechanical consequence that partons are correlated with each other across the bound state hadrons, rather than being identified with individual PDFs and FFs. Recent results from the PHENIX experiment at the Relativistic Heavy Ion Collider will be shown which investigate effects that are predicted to be sensitive to the nonperturbative factorization breaking.

  123. Condensed-Matter Physics & Materials Science Seminar

    "Creating Spatially Ordered States in Monolayer Graphene"

    Presented by Abhay Pasupathy, Columbia University

    Friday, October 21, 2016, 1:30 pm
    ISB Bldg. 734, Conf. Rm. 201 (upstairs)

    Hosted by: 'Cedomir Petrovic'

    Electrons in graphene at the Fermi level have chirality or handedness that arises from the honeycomb structure in real space. This chirality is responsible for many of the fascinating electronic properties of graphene such as Klein tunneling. In this talk, I will describe two related scanning tunneling microscopy experiments that probe the chiral nature of the electronic states in graphene. First, I will describe an experiment where we observe the chiral symmetry of graphene to be broken, resulting in a bond-ordered phase called Kekule order. I will show that this new phase in monolayer graphene can be induced by adatoms on the surface of graphene which interact electronically with each other. In a related experiment, I will describe the electronic structure of graphene in the presence of a circular potential well that separates the sheet into p (hole) and n (electron) doped regions. Electrons in these wells spend a finite amount of time before transitioning out of the well, resulting in quasibound states that can be measured in scanning tunneling spectroscopy. Due to the chirality of the electrons in graphene, the transition probabilities at the p-n junction are governed by the physics of Klein tunneling, which can be understood from the details of the energies and wavefunctions of the quasibound states observed in experiment.

  124. HET Lunch Discussions

    "Chiral heavy fermions one more time: pheno & new search strategies"

    Presented by Shaoul Bar-Shalom, Technion

    Friday, October 21, 2016, 12:15 pm
    Building 510, Room 2-160

    Hosted by: 'Christoph Lehner'

  125. Particle Physics Seminar

    "Large area GEM detectors with zigzag readouts"

    Presented by Aiwu Zhang, Florida Institute of Technology

    Thursday, October 20, 2016, 3 pm
    Small Seminar Room, Bldg. 510

    Hosted by: 'Xin Qian'

    Gaseous Electron Multiplier (GEM) detectors have been widely studied and applied in many experiments. The so called zigzag readout has been studied for reading out large area GEM detectors for tracking purposes. Using of the zigzag readout can significantly reduce number of electronic channels and hence the cost of a detector while still preserving good spatial resolution on a detector. In this presentation, I will first briefly review the GEM detectors and their applications, then I will focus on the R&D activities on GEM detectors with zigzag readout for tracking at a future electron ion collider (EIC), I'll also cover some potential applications of large area GEM detectors and the zigzag readout for other experiments.

  126. RIKEN Lunch Seminar

    "Chiral magnetic effect and anomalous transport from real-time lattice simulations"

    Presented by Niklas Mueller, Heidelberg University

    Thursday, October 20, 2016, 12:30 pm
    Building 510, Room 2-160

    Hosted by: '''Hiroshi Oki'''

    We present a first-principles study of anomaly induced transport phenomena by performing real-time lattice simulations with dynamical fermions coupled simultaneously to non-Abelian SU(Nc) and Abelian U(1) gauge fields. Investigating the behavior of vector and axial currents during a sphaleron transition in the presence of an external magnetic field, we demonstrate how the interplay of the chiral magnetic and chiral separation effect leads to the formation of a propagating wave. We further analyze the dependence of the magnitude of the induced vector current and the propagation of the wave on the amount of explicit chiral symmetry breaking due to finite quark masses. Further we perform simulations using overlap-fermions for the first time in real-time, showing that in the classical statistical regime they can be related to the Wilson formulation.

  127. Joint: YITP/HET

    "A New Angle on Jet Substructure"

    Presented by Jesse Thaler, MIT

    Wednesday, October 19, 2016, 2:30 pm
    YITP Seminar Room

    Jet substructure has emerged as a key tool for new physics searches at the LHC, particularly for signals that involve highly Lorentz-boosted top quarks and electroweak bosons. In this talk, I present a suite of powerful jet substructure observables that were discovered by systematically studying the soft and collinear singularities of QCD. These new observables are based on N-particle energy correlations, using a novel angular weighting function to yield improved performance over previous techniques.

  128. Nuclear Physics Seminar

    "Phase diagram of the strongly interacting matter in an effective field theory approach"

    Presented by Gyorgy Wolf

    Tuesday, October 18, 2016, 11 am
    Small Seminar Room, Bldg. 510

    Hosted by: 'Oleg Eyser'

    In the framework of an SU(3) (axial)vector meson extended linear sigma model with additional constituent quarks and Polyakov loops, we investigate the effects of (axial)vector mesons on the chiral phase transition. The parameters of the Lagrangian are set at zero temperature and we use a hybrid approach where in the effective potential the constituent quarks are treated at one-loop level and all the mesons at tree-level. We have four order parameters, two scalar condensates and two Polyakov loop variables and their temperature and baryochemical potential dependence are determined from the corresponding field equations. We investigate the thermodynamics of the system, and at zero temperature we compare our results with lattice calculations. We calculate th phase diagram and the scalar meson masses in the hot and dense medium.

  129. HET Lunch Discussions

    "Constraining the Higgs trilinear coupling"

    Presented by Pier Paolo Giardino, BNL

    Friday, October 14, 2016, 12:15 pm
    Building 510, Room 2-160

    Hosted by: ''Christoph Lehner''

  130. RIKEN Lunch Seminar

    "Kibble-Zurek dynamics and universal off-equilibrium scaling of critical cumulants in the QCD phase diagram"

    Presented by Raju Venugopalan, BNL

    Thursday, October 13, 2016, 12:30 pm
    Building 510, Room 2-160

    Hosted by: ''Hiroshi Oki''

    We exploit the universality between the QCD critical point and the three dimensional Ising model to derive closed form expressions for non-equilibrium critical cumulants on the crossover side of the critical point. Novel expressions are obtained for the non-Gaussian Skewness and Kurtosis cumulants; our results reveal that they can differ both in magnitude and sign from equilibrium expectations. We show further that key elements of the Kibble-Zurek framework of non-equilibrium phase transitions can be employed to describe the dynamics of these critical cumulants. As a consequence, observables sensitive to critical dynamics in heavy-ion collisions are expressible as universal scaling functions and thereby provide powerful model independent guidance in searches for the QCD critical point.

  131. HET/RIKEN Seminar

    "Cannibal Dark Matter"

    Presented by Marco Farina, Rutgers University

    Wednesday, October 12, 2016, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: '''Pier Paolo Giardino'''

  132. Nuclear Physics Seminar

    "Transverse polarization of Lambda/anti-Lambda in e+e- annihilation at Belle and the K-Long muon (KLM) system of Belle-II detector"

    Presented by Yinhui Guan, Indiana University

    Tuesday, October 11, 2016, 11 am
    Small Seminar Room, Bldg. 510

    Hosted by: 'Oleg Eyser'

    Spontaneous Lambda polarization has been observed in unpolarized pp collisions years ago while the precise mechanism behind it remains unknown. It is assumed that the so called polarizing Fragmentation Function(FF) plays a important role in this effect. The polarizing FF is of great interest not only because it is strongly connected to the spin structure of hadrons, but also it is chiral-even and the sign is possible to be unambiguously measured so it provides a unique opportunity to test the universality of the FFs. The large e+e- annihilation data sample collected by the Belle experiment at the KEKB storage ring allows a precision study of the production of transversely polarized hyperons and check our current understanding of the associated QCD dynamics. The measurement of transverse Lambda/anti-Lambda polarization in e+e- annihilation in the inclusive Lambda production processes at Belle will be presented and discussed. The Belle II detector and SuperKEKB, the upgrade of Belle detector and KEKB collider, are being constructed at the KEK laboratory in Tsukuba, Japan. The K-Long and muon system of Belle II, which provides the K-Long and muon identification, consists of an alternating sandwich iron plates and active detector elements located outside of the superconducting solenoid. The Belle KLM based on glass-electrode resistive plate chambers(RPC) has demonstrated good performance. However, the long dead time of the RPCs during the recovery of the electric field after a discharge significantly reduces the detection efficiency under high backgrounds fluxes. So the endcap RPCs and two inner layers of barrel RPCs will be retired and replaced with scintillators in Belle II. This talk will introduce the Belle-II detector, mainly KLM system and the related offline software, KLM alignment and the current status of cosmic ray test (CRT).

  133. Condensed-Matter Physics & Materials Science Seminar

    "X-ray Imaging via Bragg CDI: From Ultrafast Physics to Defect Dynamics"

    Presented by Andrew Ulvestad, Argonne National Laboratory

    Friday, October 7, 2016, 11 am
    ISB Bldg. 734, Conf. Rm. 201 (upstairs)

    Hosted by: ''Ian Robinson''

    Bragg coherent diffractive imaging is an emerging x-ray imaging technique capable of resolving both defect and ultrafast dynamics in nanocrystals with three-dimensional detail and nanometer resolution. This ability to study single nanocrystals in their reactive environments opens new insight into a broad range of materials science questions, including how to improve materials that convert heat into electricity, understanding degradation in advanced battery cathodes, and probing the structure-stability relationship in fuel cell catalysts. Here I will discuss Bragg CDI studies of phonon dynamics in Zinc Oxide and defect dynamics in thin film grains driven by temperature. Finally, I will touch on future directions for BCDI with the anticipated increase in coherent flux at upgraded synchrotrons.

  134. RIKEN Lunch Seminar

    "Complex spectrum of QCD at finite density"

    Presented by Hiromichi Nishimura, RBRC

    Thursday, October 6, 2016, 12:30 pm
    Building 510, Room 2-160

    Hosted by: ''Hiroshi Oki''

    We consider the effective action of the Polyakov loop at finite temperature and density. Using simple models, we show two novel manifestations of the sign problem in QCD: the non-hermitian transfer matrix and the complex saddle point. As a result the mass matrix associated with the Polyakov loop becomes complex, and it gives rise to damped oscillatory behavior in Polyakov loop correlation functions, which reflects oscillatory behavior in the quark-number density reminiscent of density-density correlation functions in liquids. The complex spectrum should be observable in lattice simulations of QCD and may provide a test for finite-density algorithms.

  135. Center for Functional Nanomaterials Seminar

    "Reversed Nanoscale Kirkendall Effect in Au-InAs Hybrid Nanoparticles"

    Presented by Anatoly I. Frenkel, Department of Materials Science and Engineering, Stony Brook University / Chemistry Department, Brookhaven National Laboratory

    Thursday, October 6, 2016, 11 am
    Bldg 735, Conference Room A

    Hosted by: ''Eric Stach''

    Metal-semiconductor hybrid nanoparticles (NPs) have synergistic properties that have been exploited in photocatalysis, electrical, and optoelectronic applications. Rational design of hybrid NPs requires the knowledge of the underlying mechanisms of diffusion of the metal species through the nanoscale semiconductor lattice. One extensively studied process of diffusion of two materials across the nanoparticle surface is known as the nanoscale Kirkendall effect. There, an atomic species A with the lower diffusion rate enters the nanocrystal slower than the B species diffusing from the nanocrystal outward. As a result, voids are formed in B, providing an interesting avenue for making hollow nanocrystals. We used time-resolved X-ray absorption fine-structure spectroscopy, X-ray diffraction and electron microscopy to monitor the diffusion process of Au atoms through InAs nanocrystals in real time. In this system the diffusion rate of the inward diffusing species (Au) is faster than that of the outward diffusion species (InAs), which results in the formation of a crystalline metallic Au core surrounded by an amorphous, oxidized InAs shell with voids in it. These observations indicate that in hybrid Au-InAs NPs the rarely observed "reversed nanoscale Kirkendall effect" is in play. It presents a potentially new way to synthesize unique nanoscale core-shell structures.

  136. Particle Physics Seminar

    "Dark Interactions: perspective from theory and experiment"

    Thursday, October 6, 2016, 9 am
    Small Seminar Room, Bldg. 510

    Hosted by: 'Michael Begel'

  137. Condensed-Matter Physics & Materials Science Seminar

    "The numerical renormalization group as a viable multi-band impurity solver for dynamical mean-field theory"

    Presented by Katharina Stadler, Ludwig-Maximilians-Universitaet Muenchen, ASC, Germany

    Wednesday, October 5, 2016, 1:30 pm
    Bldg. 734, ISB Conference Room 201 (upstairs)

    Hosted by: 'Gabi Kotliar'

    In my talk I will present the numerical renormalization group (NRG) as a viable multi-band impurity solver for dynamical mean-field theory (DMFT). NRG offers unprecedented real-frequency spectral resolution at arbitrarily low energies and temperatures. It is thus perfectly suited to study "Hund metals" [1], which show - in experiments and theoretical DMFT calculations - puzzling behavior at unusually low energy scales, like Fermi-liquid behavior at low temperatures, a coherence-incoherence crossover with increasing temperature [2, 3] and fractional power laws for the imaginary part of the Matsubara self-energy in the incoherent regime, discovered already early on with continuous time quantum Monte Carlo (CTQMC) as DMFT solver [3]. I will explicitly demonstrate the advantages of NRG+DMFT in the context of a channel-symmetric three-band Anderson-Hund model on a Bethe lattice at 1/3 filling (with NRG exploiting the non-abelian SU(3) channel symmetry to reduce numerical costs) [4]. In contrast to CTQMC, our NRG+DMFT calculations finally settled the existence of a Fermi-liquid ground state. We further revealed new important insights: our real-frequency one-particle spectral function shows a coherence-incoherence crossover (driven by Hund J rather than Hubbard U) and strong particle-hole asymmetry, which leads to the above-mentioned apparent fractional power laws; two-stage screening, where spin screening occurs at much lower energies than orbital screening ("spin-orbital separation"); and zero-temperature spectral properties that are similar with or without DMFT self-consistency, in contrast to Mott-Hubbard systems, where the DMFT self-consistency opens a gap. A recent reformulation of NRG, called "interleaved NRG" (iNRG) [5, 6] allows to tackle more realistic models of Hund metals where channel symmetries are generally broken (for example, due to crystal field splitting).

  138. Nuclear Physics Seminar

    "EoSization in holgraphic shockwave collision"

    Presented by Maximilian Attems, University of Barcelona

    Tuesday, October 4, 2016, 11 am
    Small Seminar Room, Bldg. 510

    Hosted by: 'Oleg Eyser'

    Ever since fast hydrodynamization has been observed in heavy ion collisions the understanding of the very early non-equilbrium stage of such collisions has been a topic of intense research. We use the gauge/string duality to model the creation of a strongly coupled Quark-Gluon plasma in a non-conformal gauge theory. This study is the first non-conformal holographic simulation of a heavy ion collision. We extract new physics as compared to the conformal case such as the non-trivial equation of state and the presence of a sizeable bulk viscosity. Non-conformality gives rise to an increase of the relaxation times of the resulting plasma. Furthermore, if the bulk viscosity is large enough then the plasma becomes well described by hydrodynamics before the equilibrium equation of state becomes applicable. This time we refer to as the EoSization time. This EoSization process is a new non-conformal relaxation channel involving the evolution of energy density and average pressure. It is exciting to see this new channel for bulk viscsosity values well below QCD critical temperature estimates.

  139. HET Lunch Discussions

    "Gravitational Wave Signatures of Sub-Millimeter Primordial Black Holes"

    Presented by Hooman Davoudiasl, BNL

    Friday, September 30, 2016, 12:15 pm
    Building 510, Room 2-160

    Hosted by: 'Christoph Lehner'

  140. Environmental & Climate Sciences Department Seminar

    "Viscous organic aerosol particles and water uptake: From observations of internal diffusion fronts in single, levitated particles to estimating kinetic limitations under atmospheric conditions"

    Presented by Dr. Ulrich Krieger, Institut für Atmosphäre und Klima, Zürich, Switzerland

    Friday, September 30, 2016, 11 am
    Conference Room Bldg 815E

    Hosted by: 'Robert McGraw'

    Field measurements in the recent past have shown that secondary organic aerosol (SOA) particles are often amorphous glasses or highly viscous liquids under dry and/or cold conditions. Chemical and physical processes occurring in the interior of the aerosol particle and at the gas/particle interface are influenced by the viscous state in which condensed-phase diffusion is slows down considerably. I will discuss measurements of water diffusion in single, levitated aerosol particles for a number of model systems of SOA. In particular, I will show how Mie-resonance spectroscopy allows to "image" diffusion fronts within these particles and discuss atmospheric implications of kinetic limitations of water uptake.

  141. Particle Physics Seminar

    "Sterile Neutrino Search at Daya Bay"

    Presented by Dr. Wei Tang, BNL

    Friday, September 30, 2016, 10 am
    Small Seminar Room, Bldg. 510

    Hosted by: ''Xin Qian''

    Daya Bay recently updated the light sterile neutrino searching results with 621 days of data. The new analysis has 3.6 times of statistics, improved energy calibration as well as the reduced backgrounds compared to the previous publication. The resulting limits on sin22theta14 are improved by approximately a factor of two over previous results and constitute the most stringent constraints to date in the Delta m2_41 < 0.2 eV2 region. The result is combined with those from MINOS and Bugey-3 experiments to constrain oscillation into light sterile neutrinos. The three experiments are sensitive to complementary regions of parameter space, enabling the combined analysis to probe regions allowed by the LSND and MiniBooNE experiments in 3+1 neutrino framework. Stringent limits on sin22theta_mue are set over six orders of magnitude in the sterile mass-squared splitting Delta m2_41. In this talk, I will show details of the recent update sterile neutrino search at Daya Bay, the reproduction of Bugey-3's results and the combination of Daya Bay, Bugey-3 and MINOS results.

  142. Particle Physics Seminar

    "Simulating the large-scale structure in different density environments"

    Presented by Chi-Ting Chiang, Stony Brook University

    Thursday, September 29, 2016, 3 pm
    Small Seminar Room, Bldg. 510

    Hosted by: '''Anze Slosar'''

    Understanding structure formation is one of the most important issues in modern cosmology. In particular, in the era of big astronomical data, connecting observation and theory is crucial to improve precision cosmology, and possibly probe new physics. The observables of large-scale structure, such as galaxy number density, generally depend on the density of the environment. This dependence can traditionally be studied by performing gigantic cosmological N-body simulations and measuring the observables in different density environments. Alternatively, we can perform so-called ``separate universe simulations,'' in which the effect of the environment is absorbed into the change of the cosmological parameters. In other words, an overdense universe is equivalent to a positively curved universe, and the structure formation would change accordingly. In this talk, I will introduce the separate universe mapping, and present how the power spectrum and halo mass function changes in different density environments, which are related to the squeezed-limit bispectrum and the halo bias, respectively. I will also discuss our recent progress on extending this approach to multiple fluids such as dynamic dark energy and massive neutrinos.

  143. Particle Physics Seminar

    "Measurement of muon g-2 and EDM with ultra-cold muon beam at J-PARC"

    Presented by Dr. Tsutomu Mibe, KEK

    Thursday, September 29, 2016, 10 am
    Small Seminar Room, Bldg. 510

    Hosted by: 'Xin Qian'

    The J-PARC E34 experiment aims to measure the anomalous magnetic moment (g-2) and electric dipole moment (EDM) of the positive muon with a novel technique utilizing an ultra-cold muons accelerated to 300 MeV/c and a 66 cm-diameter compact muon storage ring without focusing electric field. This measurement will be complementary to the previous BNL E821 experiment and upcoming FNAL E989 experiment with the muon beam at the magic momentum 3.1GeV/c in a 14 m-diameter storage ring. In this talk, I'd like to discuss the present status and prospects.

  144. HET Seminar

    "Lattice QCD for Neutrino Physics"

    Presented by Aaron Meyer, University of Chicago

    Wednesday, September 28, 2016, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: 'Mattia Bruno'

  145. Physics Colloquium

    "Synthetic gene circuits: New research tools for quantitative biology"

    Presented by Gabor Balazsi, Stony Brook U

    Tuesday, September 27, 2016, 3:30 pm
    Large Seminar Room, Bldg. 510

    Hosted by: 'Peter Petreczky'

    Synthetic biology is a new interdisciplinary field that designs and builds artificial biological systems, using principles from physics, engineering, and mathematics. Recent success stories include the massive, low-cost synthesis of the anti-malaria drug artemisinin, and the construction of genetic switches, oscillators and logic gates. In my laboratory we build synthetic gene circuits and use them as new research tools to precisely perturb cells and watch how they respond. This way, we hope to develop a predictive, quantitative understanding of biological processes such as microbial drug resistance and cancer. We have developed an expanding library of synthetic gene regulatory circuits first in yeast, and then in cancer cells for this purpose. I will illustrate through a few examples how we can gain a deeper, quantitative understanding of microbial drug resistance and cancer using synthetic gene circuits.

  146. HET Lunch Discussions

    "Playing with Time in the Schwarzschild Metric"

    Presented by Micheal Creutz, BNL

    Friday, September 23, 2016, 12:15 pm
    Building 510, Room 2-160

    Hosted by: ''Christoph Lehner''

  147. Particle Physics Seminar

    "SB/BNL Joint Cosmo Seminar"

    Thursday, September 22, 2016, 12 pm
    Stony Brook

    Hosted by: 'Anze Slosar'

  148. Joint YITP/HET Seminar

    "Towards precision jet physics at the LHC"

    Presented by Matt Schwartz, Harvard

    Wednesday, September 21, 2016, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: ''Amarjit Soni''

  149. Nuclear Physics Seminar

    "Hadronization studies at HERMES"

    Presented by Charlotte Van Hulse, University of the Basque Country

    Tuesday, September 20, 2016, 11 am
    Small Seminar Room, Bldg. 510

    Hosted by: 'Oleg Eyser'

    The HERMES experiment at DESY, Hamburg, collected data using the 27.6 GeV HERA electron/positron beam incident on a variety of gaseous targets, among others transversely polarized and unpolarized hydrogen as well as unpolarized deuterium, neon, krypton, and xenon. From the data taken with hydrogen and deuterium targets, charge-separated kaon and pion multiplicities in semi-inclusive deep-inelastic scattering were extracted. These allow the study of the spin-independent fragmentation of quarks into the identified hadrons. Hadronization in the nuclear environment studied via the analysis of multiplicities provides additional qualitative information on the space-time evolution of hadron formation. From the analysis of the azimuthal distribution of the produced hadrons, spin effects in hadronization can be studied, in particular the Collins fragmentation function, which describes the formation of a transversely polarized quark into an unpolarized hadron. The latter fragmentation function can also be accessed independently analyzing semi-inclusive deep-inelastic scattering events using the transversely polarized hydrogen target. The study of two-pion and two-kaon production from this same data sample provides access to a series of di-hadron fragmentation functions, including those in which the transverse spin of the fragmenting quark is transferred to the relative orbital angular momentum of the hadron pair. An overview of the results of the mentioned analyses as well as their possible interpretations will be presented.

  150. HET Lunch Discussions

    "Weak decays beyond NLO II"

    Presented by Mattia Bruno, BNL

    Friday, September 16, 2016, 12:15 pm
    Building 510, Room 2-160

    Hosted by: 'Christoph Lehner'

  151. Condensed-Matter Physics & Materials Science Seminar

    "Interplay of structure, magnetism and superconductivity in the 112 Fe based superconducting family"

    Presented by Ni Ni, UCLA

    Thursday, September 15, 2016, 1:30 pm
    Seminar Room, 2nd Fl, ISB Bldg. 734

    Hosted by: ''Robert Konik''

    Both cuprates and Fe-based superconductors, the two known high Tc superconducting families, show rich emergent phenomena near the superconductivity (SC). To understand the mechanism of unconventional SC, it is crucial to unravel the nature of these emergent orders. The 112 Fe pnictide superconductor (FPS), Ca1−xRExFeAs2 (CaRE112), shows SC up to 42 K, the highest bulk Tc among all nonoxide FPS. Being an exceptional FPS where the global C4 rotational symmetry is broken even at room temperature, it is important to extract the similarities and di?erences between 112 and other FPS so that critical ingredients in inducing SC in FPS can be ?ltered. In this talk, I will review current progress in the study of 112. The comparison between Co doped CaLa112 and Co doped 10-3-8 will be made and the importance of interlayer coupling will be discussed.

  152. RIKEN Lunch Seminar

    "Quark Polarization at Small x"

    Presented by Matt Sievert, BNL

    Thursday, September 15, 2016, 12:30 pm
    Building 510, Room 2-160

    Hosted by: ''Hiroshi Oki''

    Parton distribution functions in the small-x limit have long been known to be dominated by gluon bremsstrahlung produced in the BFKL and BK / JIMWLK evolution mechanisms. This small-x gluon cascade generates high color-charge densities, leading to the effective semi-classical theory known as the color-glass condensate (CGC). While this unpolarized small-x evolution has been thoroughly studied, the evolution of the polarized parton distributions is much less understood. Using modern CGC techniques, we calculate the small-x evolution equations for the helicity distribution of polarized quarks. This polarized small-x evolution is quite different from the unpolarized evolution, bringing in much more complicated dynamics which transfer spin to small x. Although the quark polarization at small x is initially suppressed, strong evolution corrections substantially enhance the amount of spin at small x. By solving our equations (numerically, in the large-Nc limit), we compute the asymptotic behavior of the quark helicity at small x, and we discuss the implications of this result for the outstanding Proton Spin Puzzle.

  153. HET

    "Multi-Component Dark Matter through a Radiative Higgs Portal"

    Presented by Gopolang Mohlabeng, University of Kansas

    Wednesday, September 14, 2016, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: '''Sally Dawson'''

  154. Physics Colloquium

    "Transport in QCD: A Theorist's View"

    Presented by Guy Moore, University of Darmstadt

    Tuesday, September 13, 2016, 3:30 pm
    Large Seminar Room, Bldg. 510

    Hosted by: ''Robert Pisarski''

    After summarizing the role of hydrodynamics in QCD and heavy ion physics, I will focus on what we know, theoretically, about the transport coefficients which enter hydrodynamics. I will focus on shear viscosity and heavy quark diffusion. I will explain the problems and limitations of the theoretical tools we have, and how we hope to push them a little farther — and better characterize their weaknesses.

  155. Nuclear Physics Seminar

    "Finite-Size Scaling of Susceptibility and Non-Gaussian Fluctuations Near the QCD Critical Point"

    Presented by Roy Lacey, Stony Brook University

    Friday, September 9, 2016, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: 'Matthew Sievert'

    A major experimental theme at the Relativistic Heavy Ion Collider (RHIC), is the the study of observables that could signal the location and character of the critical endpoint (CEP) – the end point of the first-order coexistence curve in the temperature vs. baryon chemical potential (T, μB) plane of the phase diagram for Quantum Chromodynamics (QCD). I will show that Finite-Size Scaling of measurements linked to both the susceptibility and critical fluctuations, lead to scaling functions which provide a potent tool for locating and characterizing the CEP. A recent estimate of the location of the CEP and the associated critical exponents used to assign the order of the transition and its universality class will be presented as well.

  156. HET Lunch Discussions

    "The Beryllium anomaly and a possible particle physics interpretation"

    Presented by Eder Izaguirre, BNL

    Friday, September 9, 2016, 12:15 pm
    Building 510, Room 2-160

    Hosted by: 'Christoph Lehner'

  157. Nuclear Physics Seminar

    "Current state of nPDFs, LHC and future possibilities"

    Presented by Pia Zurita, Universidade de Santiago de Compostela, Spain, Spain

    Thursday, September 1, 2016, 2 pm
    2-160

    Hosted by: 'Thomas Ullrich'

    In the last years, significant progress has been made in obtaining nuclear PDFs (nPDFs) from data. In addition to the theoretical improvements routinely used in modern extractions of free proton PDFs, the most recent determinations of nPDFs have move towards truly global QCD analyses of nuclear effects. Furthermore, the end of the Run at the LHC I has shown promising results for the improvement of our knowledge on the nuclear medium. In this talk I will discuss the current state of nPDFs, comparing the most recent determinations, and address the possible impact of LHC and future colliders' data on the nPDFs.

  158. HET Lunch Discussions

    "Survey of algorithms for finite lattice"

    Presented by Taku Izubuchi, BNL

    Friday, August 26, 2016, 12:15 pm
    Building 510, Room 2-160

    Hosted by: ''Christoph Lehner''

  159. Condensed-Matter Physics & Materials Science Seminar

    "The first-principles study of structural, electronic, and magnetic properties of strongly correlated materials: DFT+DMFT approach."

    Presented by Hyowon Park, University of Illinois

    Thursday, August 25, 2016, 3 pm
    Bldg. 734, ISB Conference Room 201 (upstairs)

    Hosted by: ''Neil Robinson''

    Strongly correlated materials including transitional metal oxides and heavy fermion materials exhibit novel structural, electronic, and magnetic properties. The first-principles study of these unusual properties requires a theoretical description that goes beyond density functional theory to treat strong correlation effects properly. In this talk, I will show that the density functional theory plus dynamical mean field theory (DFT+DMFT) method enables realistic and quantitative calculations of those properties in good agreement with experimental spectroscopic measurements. First, I will clarify the nature of the insulating phase in bulk rare-earth nickelates using DFT+DMFT and determine the structural and metal-insulator phase diagram. I will also present DFT+DMFT results of structural and electronic properties in artificially structured LaNiO3/LaAlO3 superlattices under strains. Calculation results of layer-resolved orbital polarization will be compared to recent X-ray absorption spectroscopy data and analyzed in terms of structural and quantum confinement effects. Finally, I will show the momentum and frequency dependent magnetic excitation spectra in CePd3 computed using DFT+DMFT and explain that the calculated spectra based on realistic band excitations are in good agreement with the inelastic neutron scattering data measured in this material.

  160. Particle Physics Seminar

    "Testing the Standard Model with the lepton g-2"

    Presented by Massimo Passera, INFN

    Thursday, August 25, 2016, 3 pm
    Small Seminar Room, Bldg. 510

    Hosted by: ''William Marciano''

  161. Nuclear Physics Seminar

    "Multiplicity Fluctuations in Dilute-Dense Scattering"

    Presented by A. H. Mueller, Columbia University

    Friday, August 19, 2016, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: 'Matthew Sievert'

    The general features of the event-by-event fluctuations of the multiplicity of gluons produced in the scattering of a dilute "hadron" off a large nucleus are discussed. Analytic calculations are possible in "semi-realistic" circumstances.

  162. HET Lunch Discussions

    "An update on a precise first-principles determination of the muon g-2"

    Presented by Christoph Lehner, BNL

    Friday, August 19, 2016, 12:15 pm
    Building 510, Room 2-160

    Hosted by: 'Christoph Lehner'

  163. Condensed-Matter Physics & Materials Science Seminar

    "Controlling the metal-insulator transition in LaNiO3"

    Presented by Frederick Walker, Yale University

    Thursday, August 18, 2016, 1:30 pm
    Bldg. 734, ISB Bldg., Conf Room 201 (upstairs)

    Hosted by: 'Mark Dean'

    New materials are needed to advance electronic, optical and energy materials beyond current technology trends. Perovskite oxides can potentially meet these needs due to their flexibility and unique functional properties. In bulk materials, these properties are accessed through modifications of physical and electronic structure through cation substitution in the perovskite lattice. An even larger phase space of properties and functionalities is possible when these materials are combined in thin film heterostructure form using molecular beam epitaxy. The sensitivity of the resulting properties on interface structure often dominates device function. Uncovering a microscopic understanding of emergent properties at such interfaces is challenging due to the small volume of material present. In this talk, we show how a combination of first principles theory and experiment can be used to develop a non-volatile, three terminal switch. The device is implemented by using the perovskite LaNiO3 as a conducting channel and a ferroelectric gate. The approach to developing this switch involves synchrotron x-ray characterization of picoscale structural distortions for LaNiO3 heterostructures, including LaNiO3-vacuum, LaNiO3-band insulator, and LaNiO3-ferroelectric. The consequences of the picoscale distortions are strong modulations of the measured electronic transport as a function of interface and ferroelectric polarization direction. Quantitative comparisons of the structure with first principles theory show excellent agreement. Theory provides an understanding of how the picoscale distortions at the interface result in changes in orbital occupation and band properties of both the nickelate and ferroelectric. These insights inspire new principles for designing ferroelectric heterostructures that show record non-volatile resistance modulations.

  164. HET/RIKEN Seminar

    "Standard Model Vacuum Stability with a 125 GeV Higgs Boson"

    Presented by Stefano Di Vita, DESY

    Friday, August 12, 2016, 12:15 pm
    Building 510, Room 2-160

    Hosted by: ''Pier Paolo Giardino''

  165. Special Nuclear Theory Seminar

    "Scalar mesons in low-energy QCD and probing their properties within generalized linear sigma model"

    Presented by Amir Fariborz, SUNY Institute of Technology at Utica

    Tuesday, August 9, 2016, 11 am
    Small Seminar Room, Bldg. 510

    Hosted by: 'Rob Pisarski'

    Unlike the light pseudoscalar mesons, understanding the properties of light scalar mesons (particularly, their quark substructure) is known to be quite nontrivial. Scalar mesons are important from the theoretical point of view because they are effectively the Higgs bosons of QCD and induce chiral symmetry breaking, and therefore, are probes of the QCD vacuum. Scalars are also important from a phenomenological point of view, as they are crucial intermediate states in Goldstone boson interactions away from threshold; in a range of energy that is too high for a chiral perturbation theory framework, and too low in the context of the perturbative QCD. The physics of scalar mesons has a great impact on our understanding of important issues in strong interactions such as the diquarks, glueballs, hybrids, violation of isospin, low energy hadron phenomenology, instantons, and final-state interaction of pseudoscalar mesons. Moreover, physics of scalar mesons can provide significant insights outside its immediate focus of low-energy QCD such as, for example, in studies of decay Ds to f0(980) e+ ve or decay Bs to J/psi f0(980) measured by LHCb. In this talk, the status of the scalar mesons will be briefly reviewed and the generalized linear sigma model of low-energy QCD for understanding their properties will be presented. Specifically, the underlying symmetries (and their breakdown) for designing the generalized linear sigma model, as well as various contacts with experiment for fixing the free paremeters of the model will be discussed in some details. Several predictions for various low-energy processes as well as the application of this model to studies of heavier meson decays will be given, and directions for further extensions of the model will be discussed.

  166. Nuclear Physics Seminar

    "Polarization phenomena in the Drell-Yan process"

    Presented by Werner Vogelsang, University of Tübingen

    Friday, August 5, 2016, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: 'Matthew Sievert'

    We present calculations of next-to-leading order corrections to the cross section and the single-longitudinal spin asymmetry for W boson production at RHIC. We also discuss decay lepton angular distributions in the Drell-Yan process at hadron colliders and in fixed-target experiments.

  167. Particle Physics Seminar

    "Study of the detection of supernova neutrinos"

    Presented by Hanyu Wei, Tsinghua University

    Friday, August 5, 2016, 10 am
    Small Seminar Room, Bldg. 510

    Hosted by: 'Xin Qian'

    A core-collapse supernova explosion would release an enormous amount of neutrinos, the detection of which could yield answers to many questions of supernova dynamics and neutrino physics. The collective neutrinos from all the past supernovae all over the universe (supernova relic neutrinos) are also observable, and their detection would provide us an insight of the stellar evolution and cosmology. In this talk, I will first introduce the supernova burst neutrinos as well as supernova relic neutrinos. Then, i will present the design, characteristics, and sensitivity of an online trigger system of supernova burst neutrinos at Daya Bay. I will also present a search for supernova burst neutrinos at Daya Bay using about 600 days of data. At last, a sensitivity study of the discovery potential for supernova relic neutrinos with a slow liquid scintillator will be presented, which is highly recommended to kilo-ton-scale detectors.

  168. Particle Physics Seminar

    "KamLAND-Zen and NuDot: The Future of Liquid Scintillator Detectors"

    Presented by Lindley Winslow, MIT

    Thursday, August 4, 2016, 3 pm
    Small Seminar Room, Bldg. 510

    Hosted by: ''Xin Qian''

    Large liquid-scintillator-based detectors have proven to be exceptionally effective for low energy neutrino measurements due to their good energy resolution and scalability to large volumes. The addition of directional information using Cherenkov light and fast timing would enhance the scientific reach of these detectors, especially for searches for neutrino-less double-beta decay. NuDot is a 1m3 prototype detector that will demonstrate this technique using fast photodetectors and eventually quantum-dot doped liquid scintillator. The ultimate goal is a measurement of two neutrino double-beta decay with direction reconstruction.

  169. RIKEN Lunch Seminar

    "Photon-jet Ridge at RHIC and the LHC"

    Presented by Amir Rezaeian, The Federico Santa Maria Technical University

    Thursday, August 4, 2016, 12:30 pm
    Building 510, Room 2-160

    Hosted by: ''Hiroshi Oki''

    I will talk about inclusive prompt photon and photon-jet production in p+A collisions at RHIC and the LHC. In particular, I show that photon-jet correlations in the Color Glass Condensate (CGC) picture exhibit long-range azimuthal collimation at near-side for low transverse momenta of the produced photon and jet in high-multiplicity events. These ridge-like features are strikingly similar to the observed ridge effect for di-hadron correlations at RHIC and the LHC. I show that correlations in the relative rapidity and the relative azimuthal angle between pairs of prompt photon and jet strongly depend on the gluon saturation dynamics at small-x kinematics and such measurements can help to understand the true origin of the observed di-hadron ridge in p+A collisions, and address whether the ridge is a universal phenomenon for all two particle correlations at high energy and high multiplicity events.

  170. Center for Functional Nanomaterials Seminar

    "Perovskite Photovoltaics and g-ray Radiation Detectors Research Highlights"

    Presented by Deidra R. Hodges, Ph.D., University of Texas at El Paso

    Wednesday, August 3, 2016, 11 am
    CFN, Bldg 735, Conference Room A, 1st Floor

    Hosted by: '''''Mircea Cotlet'''''

    Perovskite Photovoltaics: Renewable energies are one of the most important components of the global new energy strategy. Utilizing the power of the sun is one of the most viable ways to solve the foreseeable world's energy crisis. With increasing attention toward carbon-neutral energy production, solar electricity, or photovoltaic (PV) technology, is the object of steadily growing interest. The International Energy Agency's technology roadmap estimates that by 2050, PV will provide ~ 11% of all global electricity production & avoid 2.3 gigatonnes of CO2 emissions per year. A new solar cell material has evolved with transformative potential with laboratory efficiencies of 19.7%. Perovskite absorber materials are very inexpensive to synthesize & simple to manufacture, making them an extremely commercially viable option. Solar cell efficiencies of devices using these materials have increased from 3.8% in 2009 to a certified 20.1% in 2015, making this the fastest-advancing solar cell technology to date. These devices are also known for their high photon absorptivity, ideal direct band gaps with superior carrier charge transports, & cost-effective modes of fabrication scalability. Gama-ray Radiation Detectors: Cadmium zinc telluride (Cd1-xZnxTe or CZT), a ternary semiconductor material is well suited for good charge collection efficiency & high energy resolution room temperature x- & gamma (γ) -ray radiation detectors. In addition, these detectors can be small in size & have fast timing characteristics. Key semiconductor material properties required for high efficiency, & high energy resolution radiation detectors operable at room temperature are a high atomic number, ideal bandgap & low leakage current, high carrier mobility-lifetime (µτ) product to ensure complete charge collection, & high-purity, homogenous, & defect-free. CZT is recognized as one of the leading materials for fabrication.

  171. Nuclear Physics Seminar

    "Azimuthal anisotropy and the distribution of linearly polarized gluons in DIS dijet production at high energy"

    Presented by Adrian Dumitru, Baruch College

    Friday, July 29, 2016, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: 'Matthew Sievert'

    High Pt Dijet production in ep/eA DIS at small x (high energy) involves the expectation value of a trace of four Wilson lines, i.e. the quadrupole. At leading power the isotropic part can be expressed as the conventional Weizsacker-Williams gluon distribution. On the other hand, the distribution of linearly polarized gluons determines the amplitude of the ~ cos(2phi) anisotropy of the transverse momentum imbalance. I shall also discuss the operator that determines the next-to-leading power correction, its expectation value in a Gaussian theory (at large Nc), and the resulting .

  172. Particle Physics Seminar

    "Modeling electron- and neutrino-nucleus scattering in kinematics"

    Presented by Vishvas Pandey, Ghent University

    Thursday, July 28, 2016, 3 pm
    Small Seminar Room, Bldg. 510

    Hosted by: ''Thomas Ullrich''

    The accelerator-based neutrino-oscillation program, aimed for the measurement of oscillation parameters and observing the leptonic CP violation, is moving full steam ahead. However, the recent measurements have revealed unexpected and interesting neutrino interaction physics, and exposed the inadequacy of the relativistic Fermi gas (RFG) based Monte-Carlo generators (in describing neutrino-nucleus scatterings) resulting in large systematic uncertainties. A more detailed and careful neutrino-nucleus modeling, covering the whole experimental kinematical space, is inevitable in order to achieve the unprecedented precision goal of the present and future accelerator-based neutrino-oscillation experiments. In this talk, I will present a microscopic Hartree-Fock (HF) and continuum random phase approximation (CRPA) approach to electroweak scattering off nuclei from low energy (threshold) to the intermediate energy region. As a necessary check to test the reliability of this approach, I will first present a electron-nucleus (^12 C, ^16 O, ^40 Ca) cross section comparison (in the kinematics range of interest) with the data to validate the model. Then, I will present flux-folded (anti)neutrino cross section calculations and comparison with the measurements of MiniBooNE and T2K experiments. I will draw special attention to the contribution emerging from the low-energy nuclear excitations, at the most forward scattering bins, in the signal of MiniBooNE and T2K experiments and their impact on the non-trivial differences between muon-neutrino and electron-neutrino cross sections. These effects remain inaccessible in the (current) relativistic Fermi-gas (RFG) based Monte-Carlo generators.

  173. Nuclear Physics Seminar

    "Transport Functions from Fluid/Gravity Correspondence"

    Presented by Michael Lublinsky, Ben-Gurion University

    Friday, July 22, 2016, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: 'Matthew Sievert'

    Transport coefficients in two systems are addressed via holographic methods originating from the AdS/CFT. The first system is a neutral conformal fluid. In linearised hydrodynamics, beyond shear viscosity, all order gradient expansion can be efficiently resummed into two momenta-dependent transport coefficient functions. The second system is an e/m current coupled via chiral anomaly to an axial U(1) current. The anomaly-free all order transport coefficients are resummed into three momenta-dependent functions, the diffusion function and two conductivities. Anomaly-induced transport, resummed to all orders, generalises the chiral-magnetic effect (CME) and related phenomena. Novel, anomaly-induced non-linear effects will be presented too.

  174. Particle Physics Seminar

    "Results from the Search for eV-Sterile Neutrinos with IceCube"

    Presented by Dr. Carlos Arguelless Delgado, Massachusetts Institute of Technology

    Thursday, July 21, 2016, 3 pm
    Small Seminar Room, Bldg. 510

    Hosted by: ''Xin Qian''

    The IceCube neutrino telescope at the South Pole has measured the atmospheric muon neutrino spectrum as a function of zenith angle and energy. Using IceCube's full detector configuration we have performed a search for eV-scale sterile neutrinos. Such a sterile neutrino, motivated by the anomalies in short-baseline experiments, is expected to have a significant effect on the $\bar{\nu_\mu}$ survival probability due to matter induced resonant effects for energies of order 1 TeV. This effect makes this search unique and sensitive to small sterile mixings. In this talk, I will present the results of the IceCube sterile neutrino search.

  175. NSLS-II Friday Lunchtime Seminar Series

    "Effect of Hydrophobic and Hydrophilic Silica Nano Particles on the Dynamics of Phospholipid Films, an XPCS Investigation"

    Presented by Luigi Cristofolini, University of Parma, Italy

    Friday, July 15, 2016, 12 pm
    NSLS-II Bldg 744 (LOB 4), room 156

    Hosted by: 'L. Carr, S. Chodankar and B. Ocko'

  176. Particle Physics Seminar

    "MicroBooNE: marking a Nu era in Precision Neutrino Physics"

    Presented by Dr. Sowjanya Gollapinni, KSU

    Friday, July 15, 2016, 10 am
    Small Seminar Room, Bldg. 510

    Hosted by: 'Jyoti Joshi'

    The past few years have brought several remarkable neutrino-related discoveries and experimental anomalies indicating that these elusive particles might hold clues to some of the most profound questions in particle physics such as matter-antimatter asymmetry and the possibility of additional low-mass neutrino states. Further exploration of these clues require technological advances in neutrino detection. Liquid Argon Time Projection Chambers (LArTPCs) are imaging detectors that present neutrino interactions with the detail of bubble chambers, but with an electronic data acquisition and processing. Various efforts are ongoing at Fermi National Accelerator Laboratory (Fermilab) to develop this intriguing technology. MicroBooNE is a 170 ton LArTPC which recently started collecting data with Fermilab's Booster Neutrino Beam. In addition to addressing the recent low-energy electromagnetic anomaly observed by the MiniBooNE experiment, the exceptional particle identification capability of MicroBooNE will make it possible for the first time to measure low-energy (~1 GeV) neutrino cross-sections in argon with high precision thereby providing invaluable inputs to develop nuclear models needed for future long-baseline neutrino oscillation experiments. MicroBooNE is also leading the way for an extensive short-baseline neutrino physics program at Fermilab and also serves as a R&D project towards a long-baseline multi-kiloton scale LArTPC detector. This talk will start by giving a brief overview of LArTPC efforts at Fermilab, followed by a description of the MicroBooNE experiment, its current status and first physics results along with some future projections.

  177. Particle Physics Seminar

    "Physics with Taus at ATLAS"

    Presented by Sarah Demers

    Thursday, July 14, 2016, 3 pm
    Small Seminar Room, Bldg. 510

    Hosted by: '''Michael Begel'''

    Tau leptons are notoriously difficult particles to work with in the environment of a hadron collider due to their short lifetime and heavy enough mass for semi-hadronic decay. In this talk I will present the physics motivation for working with taus in spite of the challenges. And I will describe the work my group is involved with, from the first measurement of tau polarization at a hadron collider, to Higgs-tagging and searches for heavy, exotic particles. I will also describe the landscape for physics with taus at ATLAS as we look into Run2 and beyond.

  178. RIKEN Lunch Seminar

    "CME in Chiral Viscous Hydrodynamics"

    Presented by Shuzhe Shi, Indiana University

    Thursday, July 14, 2016, 12:30 pm
    Building 510, Room 2-160

    Hosted by: 'Hiroshi Ohki'

    Anomalous chiral transport processes, with the notable examples of Chiral Magnetic Effect (CME) and Chiral Magnetic Wave (CMW), are remarkable phenomena that stem from highly nontrivial interplay of QCD chiral symmetry, axial anomaly, and gluonic topology. The heavy ion collisions, in which topological fluctuations generate chirality imbalance, and very strong magnetic fields $|\vec{\bf B}|\sim m_\pi^2$ are present during the early stage of such collisions, provide a unique environment to study these anomalous chiral transport processes. Significant experimental efforts have been made to look for signals of CME and various other signals of anomalous chiral transport effects in heavy ion collisions. Crucial for such efforts, is the theoretical development of quantitative simulations based on hydrodynamics that incorporates chiral anomaly, implements realistic initial conditions and properly accounts for possible backgrounds. We will introduce our recent progress to understand CME qualitatively, based on a 2+1D viscous hydrodynamics framework

  179. Nuclear Physics Seminar

    "Modeling chiral criticality and its consequences for heavy-ion collisions"

    Presented by Gabor Almasi, GSI

    Friday, July 8, 2016, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: 'Matthew Sievert'

    Fluctuations of conserved charges are important observables that offer insight into the phase structure of strongly interacting matter. Around critical points, such as the chiral critical endpoint of QCD, higher order cumulants of the relevant quantities show universal behavior. The universal behavior of baryon number cumulants can be studied in effective models that lie in the same universality class as QCD. Such a model is for example the Quark Meson model. In my talk I discuss what one can learn from effective field theory studies of fluctuations and present my results obtained using the Functional Renormalization Group method in the Quark Meson model.

  180. Particle Physics Seminar

    "Dark Matter in the Cosmos-The Hunt to find it in the Laboratory"

    Presented by John D. Vergados

    Thursday, July 7, 2016, 3 pm
    Small Seminar Room, Bldg. 510

    Hosted by: 'Michael Begel'

    Matter constitutes 30% of the energy content of the Universe. The remaining 70% is what is called dark energy, which exhibits unusual repulsive gravitational interactions. On the matter sheet, only 5% is of known nature, i.e. matter such as found in atoms, in stars, in planets etc. From observations on all astrophysical and cosmological scales we know that most of it, i.e. 25%, is dark matter (DM) of unknown nature. The nature of DM is one of the most important open problems in science. The ongoing hunt for DM is multi-pronged and interdisciplinary involving cosmology and astrophysics, particle and nuclear physics as well as detector technology. In this talk we will focus on the direct detection of the dark matter constituents, the so called weakly interacting massive particles (WIMPs), in underground labs. The detection consists of measuring the energy deposited in the detector by the recoiling nucleus, after its elastic collision with a WIMP (spin independent or spin induced). In obtaining the event rates one needs models about the WIMP interaction and density in our vicinity as well as its velocity distribution. No events have so far been observed, only exclusion plots on the nucleon cross sections have been obtained, which will be discussed. Since the expected rates are very small and the usual experimental signature is not different from that of the backgrounds, we will discuss some special signatures that might aid in the analysis of the experiments such as the time dependence of the signal (modulation effect) and the option of inelastic scattering, possible in some special targets, by detecting γ-rays following the de-excitation of the nucleus.

  181. RIKEN Lunch Seminar

    "Kondo effect in QCD"

    Presented by Sho Ozaki, Keio University

    Thursday, June 30, 2016, 12:30 pm
    Building 510, Room 2-160

    Hosted by: ''Hiroshi Oki''

    In condensed matter physics, Kondo effect is known as an enhancement of electrical resistance of impure metals with decreasing temperature/energy. This phenomenon is the first known example of asymptotic freedom in physics, which is found well before the discovery of that of QCD. Kondo effect is caused by the combination of the following ingredients: In addition to the existence of a heavy impurity, (i) Fermi surface, (ii) quantum fluctuations (loop effects), (iii) non-Abelian nature of interaction (e.g. spin-flip interaction in the case of condensed matter physics). In this talk, I will discuss Kondo effect realized in QCD. We found the characteristic behavior of Kondo effect in quark matter with heavy quark impurity. There, the color exchange interaction mediated by gluons plays the role of the third condition (iii) for the appearance of Kondo effect. Furthermore, we found a novel type of Kondo effect induced by strong magnetic fields. In addition to the fact that the magnetic field dose not affect the color degrees of freedom, dimensional reduction to 1+1 dimensions and degenerate quarks in lowest Landau level play essential role for the magnetically induced QCD Kondo effect.

  182. Physics Colloquium

    "Solving the World's Problems on the Back of a Cocktail Napkin"

    Presented by Lawrence Weinstein, Old Dominion University

    Tuesday, June 28, 2016, 3:30 pm
    Large Seminar Room, Bldg. 510

    Hosted by: ''''Robert Pisarski''''

    Why don't we all drive electric cars? Does it really matter if you don't recycle that plastic water bottle? If the Sun were made of gerbils, would the Earth be incinerated? How can we answer these questions without relying on experts? This talk will cover the principles of estimating, introduce the "Goldilocks" categories of answers, and then look at some of the big (and small) questions of our time, including: Paper or plastic? Gasoline or electric cars? Should we pee before flying?

  183. Nuclear Physics Seminar

    "Two Photon Exchange and the Proton Form Factor Problem"

    Presented by Lawrence Weinstein, Old Dominion University

    Tuesday, June 28, 2016, 11 am
    Small Seminar Room, Bldg. 510

    Hosted by: 'Oleg Eyser'

    The electromagnetic form factors of the proton as measured by polarized and unpolarized electron scattering experiments differ by up to a factor of three at large momentum transfer. Calculations show that this discrepancy can be reconciled by treating the interaction in 2nd Born Approximation, i.e., including two photon exchange (TPE). While calculation of TPE effects is highly model dependent, these effects can be measured directly by comparing elastic electron-proton and positron-proton scattering. Three experiments, TPE at Jefferson Lab, VEPP-3 at Novosibirsk, and OLYMPUS at DESY, measured this. VEPP-3 and OLYMPUS used alternating monochromatic e+ and e- beams in storage rings; TPE created a tertiary mixed simultaneous e+/e- beam covering a wide range of energies. This talk will present the proton form factor problem, the experimental effort to measure the positron-electron ratio (with special emphasis on the Jefferson Lab experiment), and the results.

  184. Nuclear/Riken Theory Committee

    "On Pressure Isotropization in Heavy-Ion Collisions"

    Presented by Bin Wu, The Ohio State University

    Friday, June 24, 2016, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: ''Soeren Schlichting''

    In this talk, I would like to start with a brief introduction to non-equilibrium quantum field theory in the Schwinger-Keldysh formalism. This formalism provides a systematic way to study isotropization and other time-dependent non-equilibrium (and equilibrium) phenomena in heavy-ion collisions. I shall first discuss the foundation of classical field approximations (CSA), which is an important tool to study the evolution at very early stages. It is, however, found to be non-renormalizable. This helps us understand better the applicability of such an approximation. it is now well-known that isotropization can not be established before the breakdown of the CSA. We then use another approximation, the quasi-particle approximation (the Boltzmann equation), to study the isotropization in a scalar field theory. Our result shows explicitly the importance of quantum effects. Motivated by these observations, we have been studying whether the isotropization can be reached before the dense system of gluons, produced in the collisions of two big nuclei, becomes too dilute to be studied perturbatively in the Schwinger-Keldysh formalism. Some preliminary results shall be reported.

  185. RIKEN Lunch Seminar

    "Leading log resummation in high-energy parton production in QCD matter"

    Presented by Bin Wu, The Ohio State University

    Thursday, June 23, 2016, 12:30 pm
    Building 510, Room 2-160

    Hosted by: 'Hiroshi Oki'

  186. Physics Colloquium

    "Sterile Neutrinos as the Origin of Dark and Baryonic Matter"

    Presented by Mikhail Shaposhnikov, EPFL

    Tuesday, June 21, 2016, 3:30 pm
    Large Seminar Room, Bldg. 510

    Hosted by: 'Robert Pisarski'

    I will discuss how three sterile neutrinos alone can simultaneously explain neutrino oscillations, the observed dark matter, and the baryon asymmetry of the Universe without new physics above the Fermi scale. The experimental prospects to search for these particles will be outlined.

  187. Nuclear Physics Seminar

    "The Quest for the Origin of the Proton's Sea"

    Presented by Paul Reimer, Argonne National Lab

    Tuesday, June 21, 2016, 11 am
    Small Seminar Room, Bldg. 510

    Hosted by: 'Oleg Eyser'

    The proton is a composite particle in which the binding force is responsible for the majority of its mass. To understand this structure, the distributions and origins of the quark-antiquark pairs produced by the strong force must be measured. The SeaQuest collaboration is using the Drell-Yan process to elucidate antiquark distributions in the proton and to study the modification of these distributions when the proton is held within a nucleus. Preliminary results based on a fraction of the anticipated final data set will be presented.

  188. Nuclear Physics Seminar

    "Lattice constraints on the thermal dilepton and photon rate"

    Presented by Olaf Kaczmarek, Bielefeld University

    Friday, June 17, 2016, 2 pm
    Small Seminar Room, Bldg. 510

    We estimate the dilepton and photon production rate from an SU(3) plasma at temperatures of about 1.1 Tc to 1.5 Tc. Lattice results for the vector current correlator at zero and non-zero momenta are extrapolated to the continuum limit and analyzed with the help of phenomenological and perturbative input for the corresponding spectral functions. We compare our results with NLO weak-coupling results, hydrodynamics, and a holographic model. At vanishing invariant mass we extract the photon rate which for k>3T is found to be close to the NLO weak-coupling prediction. For k

  189. RIKEN Lunch Seminar

    "Static and dynamic screening effect on the resonant $\alpha-\alpha$ scattering in a QED plasma"

    Presented by Xiaojun Yao, Duke University

    Thursday, June 16, 2016, 12:30 pm
    Building 510, Room 2-84

    Hosted by: 'Hiroshi Oki'

  190. Environmental & Climate Sciences Department Seminar

    "High-Resolution Photography of Clouds from the Surface: Retrieval of Cloud Optical Depth down to Centimeter Scales"

    Presented by Stephen Schwartz, Environmental and Climate Sciences Department

    Thursday, June 16, 2016, 11 am
    Conference Room, Bldg 815E

    Initial results are presented of a analysis of high resolution photographs of clouds at the ARM SGP site in July, 2015. A commercially available camera having 35-mm equivalent focal length up to 1200 mm (nominal resolution as fine as 6 µrad, which corresponds to 12 mm for cloud height 2 km) is used to obtain a measure of zenith radiance of a 40 m x 40 m domain as a two-dimensional image consisting of 3456 x 3456 pixels (12 million pixels). Downwelling zenith radiance varies substantially within single images and between successive images obtained at 4-s intervals. Variation in zenith radiance found on scales down to about 10 cm is attributed to variation in cloud optical depth (COD). Attention here is directed primarily to optically thin clouds, COD less than roughly 3. A radiation transfer model used to relate downwelling zenith radiance to COD and to relate the counts in the camera image to zenith radiance, permits determination of COD and cloud albedo on a pixel-by-pixel basis. COD for thin clouds determined in this way exhibits considerable variation, for example, an order of magnitude within the 40 m domain examined here and 50% over a distance of 1 m. An alternative to the widely used areal or temporal cloud fraction, denoted radiative cloud fraction, also evaluated on a pixel-by-pixel basis, is introduced. This highly data-intensive approach, which examines cloud structure on scales 3 to 5 orders of magnitude finer than satellite products, opens new avenues for examination of cloud structure and evolution.

  191. C-AD Accelerator Physics Seminar

    ""Design Considerations for the 1.3GHz SRF Cavity for ARIEL at TRIUMF""

    Presented by Dr. Philipp Kolb, BNL

    Wednesday, June 15, 2016, 4 pm
    Bldg. 911B - Large Conf. Rm. Rm A202

    "The Advanced Rare IsotopE Laboratory (ARIEL) at TRIUMF will triple the available rare isotope beam (RIB) time for experiments. The major part of ARIEL is the 50 MeV, high intensity cw eLINAC based on 1.3GHz SRF cavities. An eventual addition to the eLINAC is a recirculating beam line to allow FEL-ERL operation in addition to the RIB production beam. To avoid multipass beam break-up (BBU), the design of the SRF cavity had to be modified to reduce the shunt impedance of dipole higher order modes (HOM). Work on the cavity design and HOM load measurements will be shown as well as results of the vertical and horizontal cavity tests."

  192. HET Seminar

    "Lattice Quantum Gravity and Asymptotic Safety"

    Presented by J. Laiho, Syracuse

    Wednesday, June 15, 2016, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: '''Sally Dawson'''

  193. Condensed-Matter Physics & Materials Science Seminar

    "Quantiative Determination of the the Fluctuations Leading to Superconductivity in Cuprates"

    Presented by Chandra Varma, University of California, Riverside

    Tuesday, June 14, 2016, 1:30 pm
    ISB Bldg. 734, Conf. Rm. 201 (upstairs)

    Hosted by: 'Peter D. Johnson'

    I will report on Laser based ARPES of unprecedented accuracy and stability (taken by the group of Xingjiang Zhou, IOP, Beijing), together with a method of analysis suggested by me (and carried out with the group of Han-Yong Choi, Asia Pacific Center for Theoretical Physics, Korea), to quantitatively extract the e↵ective frequency and momentum dependent interactions of fermions in both the full symmetry (normal) and the d-wave (pairing) symmetry in a family of cuprates. The results are remarkably simple. The principal interactions are of the form: I(k, k',w)~g0 [(1−cos(20k)cos(20'k)]F(w) They are separable functions of momentum and frequency, the first part is the repulsive part and the second part is the attractive d-wave part. F(w) is nearly constant with an upper-energy cutoff of about 0.4eV. The dimensionless coupling constant g0 ~ 0.15. These results were predicted in a theory of superconductivity and of the strange metal phase by quantum-critical fluctuation of loop-currents. They also rule out several alternatives proposed. I will also comment on the normal state and superconductivity in the Fe-based compounds.

  194. Nuclear Physics Seminar

    "Measurement of high-mass muon pairs from ultraperipheral lead-lead collisions with the ATLAS detector at the LHC"

    Presented by Peter Steinberg, BNL

    Tuesday, June 14, 2016, 11 am
    Small Seminar Room, Bldg. 510

    Hosted by: 'Oleg Eyser'

    Exclusive dimuon pairs with invariant mass Mμμ>10 GeV have been measured in ultra-peripheral lead-lead collisions at √sNN=5.02 TeV, using an integrated luminosity of 515 μb−1 taken with the ATLAS detector at the LHC in 2015. These very low-multiplicity interactions were recorded using an experimental trigger requiring a muon, low total transverse energy recorded in the calorimeter system, gaps at forward angles, and a reconstructed track. Events are selected to have no-other final state particles than a pair of opposite-sign dimuons. The cross section for dimuon pairs in Pb+Pb collisions is presented as a function of pair mass (Mμμ) and pair rapidity (Yμμ) and is well-described by calculations of Pb+Pb→Pb(*)+Pb(*)+μ+μ− using STARLIGHT 1.1 calculations. These data will improve the understanding of the strong electromagnetic fields surrounding the nucleus, which enable future UPC measurements utilizing these high energy probes.

  195. Nuclear Seminar

    "Generalizations of relativistic hydrodynamics"

    Presented by Piotr Surowka, Harvard

    Friday, June 3, 2016, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: 'Yi Yin'

    Recent developments have shown that relativistic Landau and Lifshitz hydrodynamics does not possess the most general structure. It has to generalized to account for new phenomena. I will show how to do that in two directions. One will include parity-odd transport contributions connected to anomalies, the other will capture a dissipative fluid coupled to non-Abelian degrees of freedom such as color currents or spin currents. I will mention possible applications to quark-gluon plasma and condensed matter systems.

  196. Nuclear Seminar

    "Global Hyperon Polarization in Semicentral Heavy Ion Collisions Measured by STAR"

    Presented by Mike Lisa, Ohio State University

    Tuesday, May 31, 2016, 11 am
    Small Seminar Room, Bldg. 510

    Hosted by: 'Oleg Eyser'

    Non-central collisions between ultra-relativistic heavy ions involve thousands of h-bar of angular momentum. Some of this angular momentum may be transferred to the quark-gluon plasma through shear forces that generate a vortical substructure in the hydrodynamic flow field. Understanding this fundamental femtoscopic substructure may be crucial, as we move beyond boost-invariant scenarios and rely more on sophisticated three-dimensional viscous models of the plasma. The vortical nature of the system is expected to polarize the spins of hadrons that eventually emerge. Lambda and Anti-Lambda hyperons, which reveal their polarization through their decay topology, should be polarized similarly in the direction of the system's angular momentum. These same collisions are also characterized by dynamic magnetic fields with magnitude as large as 10^{14} Tesla. Magnetic effects have been the focus of intense study in recent years due to their relevance to the Chiral Magnetic Effect (CME) and other novel phenomena. A splitting between Lambda and Anti-Lambda polarization may signal a magnetic coupling and provide a quantitative estimate of the field strength at freeze out. Physically, this strength depends on the conductivity of the QGP. The STAR Collaboration has made the first observation of global hyperon polarization along the direction of the angular momentum in non-central Au+Au collisions at Beam Energy Scan energies. Our preliminary results indicate that the QGP created at RHIC is the highest-vorticity fluid ever created in the laboratory. A magnetic splitting is hinted at, but the improved statistics and resolution achievable with future runs are required to make a definitive measurement of the magnetic field.

  197. Particle Physics Seminar

    "Searching for Sterile Neutrinos with MINOS"

    Presented by Ashley Timmons, University of Manchester

    Thursday, May 26, 2016, 3 pm
    Small Seminar Room, Bldg. 510

    Hosted by: '''Xin Qian'''

  198. RIKEN Lunch Seminar

    "Lefschetz-thimble path integral for studying the sign problem and Silver Blaze phenomenon"

    Presented by Yuya Tanizaki, RBRC

    Thursday, May 26, 2016, 12:30 pm
    Building 510, Room 2-160

    Hosted by: 'Hiroshi Ohki'

    Recently, Picard-Lefschetz theory gets much attention in the context of the sign problem, because it enables us to study the system with the complex classical action nonperturbatively by employing the semiclassical analysis. In this seminar, after its brief introduction, I will apply it to the one-site Hubbard model. This model has a severe sign problem, which looks quite similar to that of the finite-density QCD at low temperatures. By solving this model using the Lefschetz-thimble path integral, we are trying to understand the structure of the sign problem of finite-density QCD. Especially, I give a qualitative picture (or speculation) about the early-onset problem of the baryon number density, called the baryon Silver Blaze problem. The complex Langevin method will also be discussed if time allows.

  199. High Performance Computing and Programming Event

    "OpenACC and GPU Hands-on workshop"

    Presented by Presented by NVIDIA instructor Bob Crovella

    Wednesday, May 25, 2016, 8:30 am
    Stony Brook University

    NVIDIA and the Institute for Advanced Computational Science (IACS) at Stony Brook University are pleased to be organizing a 2-day High Performance Computing and Programming event. Presented by NVIDIA instructor Bob Crovella, the workshop will introduce programming techniques using OpenACC and will include topics such as optimization and profiling methods for GPU programming.

  200. Nuclear Physics Seminar

    "Exploring the Neutron Spin Structure"

    Presented by Matt Posik, Temple University

    Tuesday, May 24, 2016, 11 am
    Small Seminar Room, Bldg. 510

    Hosted by: 'Oleg Eyser'

    Jefferson Lab experiment E06-014, performed in Hall A, made measurements of the double-spin asymmetries and absolute cross sections in both the DIS and resonance regions by scattering longitudinally polarized electrons at beam energies of 4.74 and 5.89 GeV from a longitudinally and transversely polarized 3He target. Through these measurements various aspects of the neutron spin structure were investigated. The g2 nucleon spin-dependent structure function contains information beyond the simple parton model description of the nucleon. It provides insight into quark-gluon correlations and a path to access the confining local color force a struck quark experiences just as it is hit by the virtual photon due to the remnant di-quark. The quantity d2, a measure of this local color force, has its information encoded in an x2 weighted integral of a linear combination of spin structure functions g1 and g2 and thus is dominated by the valence-quark region at large momentum fraction x. To date, theoretical calculations and experimental measurements of the neutron d2 differ by about two standard deviations. Therefore E06-014 made a precision measurement of this quantity. The polarized quark distributions were also investigated through measurements of the virtual photon-nucleon asymmetry A1^n, the structure function ratio g1/F1, and quark ratio (delta d+delta d_bar)/(d+d_bar). The E06-014 results for the spin structure functions (g1,g2) on 3He, dn2, An1, (delta d+delta d_bar)/(d+d_bar), and our extractions of the neutron color electric and magnetic forces will be presented.

  201. High Performance Computing and Programming

    "OpenACC and GPU Hands-on workshop"

    Presented by Presented by NVIDIA instructor Bob Crovella

    Tuesday, May 24, 2016, 8:30 am
    Stony Brook University

    NVIDIA and the Institute for Advanced Computational Science (IACS) at Stony Brook University are pleased to be organizing a 2-day High Performance Computing and Programming event. Presented by NVIDIA instructor Bob Crovella, the workshop will introduce programming techniques using OpenACC and will include topics such as optimization and profiling methods for GPU programming.

  202. Nuclear Theory/RIKEN Seminar

    "The jet quenching parameter q-hat, and its relation to the TMDPDF"

    Presented by Abhijit Majumdar, Wayne State University

    Friday, May 20, 2016, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: '''Soeren Schlichting'''

    Based on prior work by the JET collaboration, the importance of the factorization and scale evolution of the jet quenching parameter q-hat will be outlined. This will turn out to be important for both phenomenological extractions of q-hat as well as for first principle determinations on the lattice. I will argue that for jets at RHIC and LHC, q-hat does not lie within the range of Bjoerken-x where small x effects would be considered to be dominant. Given this situation, q-hat will be found to be an integral over an operator product separated in both light-cone and transverse distance, but somewhat different from a ``traditional'' TMDPDF. This new distribution will be studied at Next-to-Leading Order and the fate of non-standard divergences discussed.

  203. HET Lunch Discussions

    "Avoiding the traps of EFT Higgs analyses"

    Presented by Tilman Plehn, Heidelberg

    Friday, May 20, 2016, 12:15 pm
    Building 510, Room 2-160

    Hosted by: ''Sally Dawson''

  204. Particle Physics Seminar

    "Searches for New Physics in boosted diboson topologies at ATLAS"

    Presented by Carmacho Toro, University of Chicago

    Thursday, May 19, 2016, 3 pm
    Small Seminar Room, Bldg. 510

    Hosted by: 'Michael Begel'

    The large increase in collision energy that the LHC reached in Run 2 provides an unprecedented opportunity to search for new physics beyond the Standard Model (SM). Various extensions of the SM predict the existence of heavy resonances at the TeV scale, which couple predominantly to the Higgs and electroweak gauge bosons. At high resonance masses the hadronic decay products of these energetic bosons tend to be highly collimated and the usual identification techniques fail to disentangle the decay products of our bosons. In this seminar I will describe the jet-substructure techniques explored by ATLAS analyses and present the results of the ATLAS searches using Run-2 data.

  205. RIKEN Lunch Seminar

    "Kosterlitz-Thouless transition and chiral rotation in external electromagnetic field"

    Presented by Gaoqing Cao, Fudan University

    Thursday, May 19, 2016, 12:30 pm
    Building 510, Room 2-160

    Hosted by: ''Daniel Pitonyak''

    In 2+1 dimensional system, the most important phase transition should be of the Kosterlitz-Thouless (KT) type. We determined the KT transition temperature T_KT as well as the mass melting temperature T^* as a function of the magnetic field. It is found that the pseudogap domain T_KT < T < T^* is enlarged with increasing strength of the magnetic field. The influence of a chiral imbalanceμ_5 was also studied. We found that even a constant axial chemical potential μ_5 can lead to inverse magnetic catalysis of the KT transition temperature in 2+1 dimensions. This is actually the de Haas—van Alphen oscillation. Furthermore, we studied the QCD vacuum structure under the influence of an electromagnetic field with a nonzero second Lorentz invariant I_2=E·B. We showed that the presence of I_2 can induce neutral pion (π_0) condensation in the QCD vacuum through the electromagnetic triangle anomaly. Within the frameworks of chiral perturbation theory at leading small-momenta expansion as well as the Nambu—Jona-Lasinio model at leading 1/Nc expansion, a universal dependence of the π_0 condensate on I_2 was found. The stability of the π_0-condensed vacuum is also discussed.

  206. HET/RIKEN Seminar

    "Higgs Pair Production in Extensions of the Standard Model"

    Presented by Ramona Groeber, Roma Tre

    Wednesday, May 18, 2016, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: 'Pier Paolo Giardino'

    Higgs pair production is not only interesting as a probe of the trilinear Higgs self-coupling, but beyond the Standard Model physics can influence the Higgs pair production cross section in many different ways, for example by new couplings, new loop particles or new resonances. In this talk, I will address the question whether we could see for the first time deviations from the Standard Model in Higgs pair production assuming that no deviations were seen before. Furthermore, for certain models I will show how higher order corrections influence the cross section.

  207. Condensed-Matter Physics & Materials Science Seminar

    "Equilibrium States and Dynamics of Spin Assemblies in Magnetic Thin Films, Heterostructures and Nanostructured Entities"

    Presented by Ramesh B. Budhani, Indian Institute of Technology Kanpur

    Tuesday, May 17, 2016, 11 am
    Building 480, Conference Room

    Hosted by: 'Lijun Wu'

    The orientation of spin assemblies in ferromagnetic thin films and nanostructures can take a variety of shapes depending on the relative strength of factors contributing to their magnetic free energy. These factors are derived from the direct quantum mechanical exchange between the electronic spins or those mediated by impurities, and those associated with the size, shape, crystallographic structure, strain, dipolar interactions and external fields. Here we present three cases where the orientational dynamics has been studied as functions of temperature, magnetic field strength and the elapsed time after acquiring a particular configuration. These studies are based on magnetic force microscopy and bulk magnetometry measurements on strain epitaxial films of La0.67Ca0.33MnO3, and lithographically patterned submicron size ring assemblies of permalloy and Co/Pd multilayers, which also form artificial spin ices. Towards the end of this lecture we will discuss interface driven magnetic and electronic phenomena in magnetic thin films.

  208. Condensed-Matter Physics & Materials Science Seminar

    "Dirac Materials"

    Presented by Alexander Balatsky, Los Alamos National Laboratory

    Monday, May 16, 2016, 11 am
    ISB Bldg. 734, Conf. Rm. 201 (upstairs)

    Hosted by: 'Peter D. Johnson'

    Discoveries of superfluid phases in 3He, high Tc superconductors, graphene and topological insulators have brought into focus materials where quasiparticles are described by same Dirac equation that governs behavior of relativistic particles. I will discuss how this class of materials, called Dirac materials, exhibits unusual universal features seen in numerous realizations: Klein tunneling, chiral symmetries and impurity resonances. Goal of this talk is to explore these similarities and discuss the unique role of symmetries that protect Dirac spectrum and possible routes to generate gaps due to many body instabilities. We will also discuss ongoing investigation of the symmetries of Dirac materials, quantum imaging, and means to control their properties. At the end we will propose to use modern tools to design artificial Dirac Materials. One example would be the design Bosonic Dirac materials that host bosonic Dirac excitations, something that would not be possible in particle physics.

  209. Nuclear Theory/RIKEN Seminar

    "Evolution of the jet opening angle distribution in holographic plasma"

    Presented by Andrei Sadofyev, MIT

    Friday, May 13, 2016, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: ''Soeren Schlichting''

    Energetic jets are particularly interesting probes of QGP created in heavy ion collisions. Recently a lot of progress was made in attempting to describe the jet evolution in holography. In this talk I'll present an application of a simple dual model to study the jet substructure starting with energy and angle distributions from pQCD. In particular I will show that there are two competing effects: (1) each individual jet widens as it propagates through plasma; (2) the final jet opening angle distribution becomes narrower since wider jets lose more energy and less likely to survive. So, the mean opening angle for jets with a given energy can easily shift toward smaller angles, even while every jet in the ensemble broadens.

  210. Particle Physics Seminar

    "Muon antineutrino oscillations at T2K"

    Presented by Jordan Myslik, University of Victoria

    Thursday, May 12, 2016, 3 pm
    Small Seminar Room, Bldg. 510

    Hosted by: 'Xin Qian'

    The T2K ("Tokai to Kamioka") experiment is a long-baseline neutrino oscillation experiment in Japan. A beam of muon neutrinos or muon antineutrinos is produced at the Japan Proton Accelerator Research Complex (J-PARC) in Tokai. The unoscillated neutrino flux is measured by the near detector complex 280 m from the proton target, and the oscillated neutrino flux is measured by the far detector, Super-Kamiokande, 295 km away. Using a beam of muon neutrinos, T2K has performed precise measurements of muon neutrino disappearance, and discovered muon neutrino to electron neutrino oscillation by measuring electron neutrino appearance. Since the summer of 2014, T2K has been taking data using a beam of muon antineutrinos, and has released the results of both a muon antineutrino disappearance analysis and an electron antineutrino appearance analysis, both using antineutrino beam data up to the summer of 2015. This talk will discuss these analyses, going into detail about the role played by the near detector, and looking at future directions.

  211. RIKEN Lunch Seminar

    "The Functional Renormalization Group Method and Delayed Magnetic Catalysis"

    Presented by Stefan Rechenberger, University of Darmstadt

    Thursday, May 12, 2016, 12:30 pm
    Building 510, Room 2-160

    Hosted by: ''Daniel Pitonyak''

    This talk will start with a very general introduction to the Functional Renormalization Group method, a powerful non-perturbative tool which can be applied to various problems. The second part of the talk will demonstrate this by discussing the influence of an external magnetic field on the chiral phase transition in the theory of strong interaction. The Functional Renormalization Group analysis shows that, driven by gluon dynamics, the chiral critical temperature decreases for small values of the magnetic field. For large values of the external field, however, the phase transition temperature increases.

  212. HET/RIKEN Seminar

    "Axions and Topology"

    Presented by Simon Mages, Forschungszentrum Juelich

    Wednesday, May 11, 2016, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: ''Tomomi Ishikawa''

    This talk will be centered around the calculation of the high temperature topological susceptibility in QCD. It will provide some background on our motivation from cosmology and particle physics, which is the dependence of axion physics on non-perturbative QCD. I will show our recent results on the quenched high temperature topological susceptibility and discuss difficulties with this conventional approach, which render dynamical studies unfeasible. I will also present our new approach based on formulating QCD on a non-orientable manifold, which is a promising candidate to solve issues related to topological freezing and the divergence of autocorrelations when approaching the continuum limit.

  213. Nuclear Theory/RIKEN seminar

    "Fluid dynamics for the anisotropically expanding quark-gluon plasma"

    Presented by Dennis Bazow, The Ohio State University

    Friday, May 6, 2016, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: ''Soeren Schlichting''

    Local momentum anisotropies become large in the early stages of the quark-gluon plasma created in relativistic heavy-ion collisions, due to the extreme difference in the longitudinal and transverse expansion rates. In such situations, fluid dynamics derived from an expansion around an isotropic local equilibrium state is bound to break down. Instead, we subsume the slowest nonhydrodynamic degree of freedom (associated with the deviation from momentum isotropy) at leading order defining a local anisoptropic quasi-equilibrium state, thereby treating the longitudinal/transverse pressure anisotropy nonperturbatively. Perturbative transport equations are then derived to deal with the remaining residual momentum anisotropies creating a complete transient effective theory called viscous anisotropic hydrodynamics. This approach has been shown to dramatically outperform viscous hydrodynamics in several simplified situations for which exact solutions exits but which share with realistic expansion scenarios the problem of large dissipative currents. We will discuss the present status of applying viscous anisotropic hydrodynamics to the phenomenological description of the quark-gluon plasma in realistic expansion scenarios.

  214. Particle Physics Seminar

    "Probing the Nature of Neutrinos with Double Beta Decay"

    Presented by Liang Yang, University of Illinois at Urbana-Champaign

    Thursday, May 5, 2016, 3 pm
    Small Seminar Room, Bldg. 510

    Hosted by: 'Xin Qian'

    Understanding fundamental properties of neutrinos is of compelling interest to the nuclear and particle physics community. The discovery of neutrino oscillations is one of our first hints of physics beyond the Standard Model. Searching for neutrinoless double decay can provide key insights into the neutrino mass generation mechanism and put stringent constraints on the absolute neutrino mass scale. Such a rare decay, if exists, would signify the Majorana nature of neutrinos and the non-conservation of lepton number. In the past decade, large ultra-low background liquid xenon detectors have emerged as a promising technology that can push the neutrinoless double beta decay search to unprecedented sensitivity. In this talk I will describe recent results and prospects of current generation experiment EXO-200, as well as the R&D program for future tonne scale detector nEXO.

  215. RIKEN Lunch Seminar

    "Vorticity in heavy-ion collisions and cold atoms"

    Presented by Xu-Guang Huang, Fudan University

    Thursday, May 5, 2016, 12:30 pm
    Building 510, Room 2-160

    Hosted by: ''Daniel Pitonyak''

    Vorticity describes the local rotation of the fluid. I will talk about our recent study of the event-by-event generation of flow vorticity in heavy-ion collisions. Several special properties of the vorticity in heavy-ion collisions will be discussed, e.g., the impact parameter dependence, the collision energy dependence, the spatial distribution, the event-by-event fluctuation of the magnitude and azimuthal direction. Vorticity can drive vector and axial current in chiral quark-gluon plasma via the chiral vortical effect. I will discuss the collective gapless mode, the chiral vortical wave, emerging from CVE and its experimental implications in heavy-ion collisions. Finally, I will consider the rotating trapped cold atomic gases and show that when there is a Weyl spin-orbit coupling such cold atomic gases provide a desktop simulator of the chiral magnetic effect and chiral separation effect.

  216. HET/RIKEN Seminar

    "Calculating TMDs and DPDs on the lattice"

    Presented by Andreas Schaefer, University of Regensburg

    Wednesday, May 4, 2016, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: 'Tomomi Ishikawa'

  217. Physics Colloquium

    "eRHIC Machine Design"

    Presented by Thomas Roser, BNL

    Tuesday, May 3, 2016, 3:30 pm
    Large Seminar Room, Bldg. 510

    Hosted by: 'Robert Pisarski'

    With the addition of a 20 GeV polarized electron accelerator to the existing Brookhaven Relativistic Heavy Ion Collider (RHIC), the world?s only high energy heavy ion and polarized proton collider, a future eRHIC facility will be able to produce polarized electron-nucleon collisions at center-of-mass energies of up to 145 GeV and cover the whole science case as outlined in the Electron-Ion Collider White Paper and endorsed by the 2015 Nuclear Physics Long Range Plan with high luminosity. The presentation will describe the eRHIC design concepts and recent efforts to reduce the technical risks of the project.

  218. High Tc Superconductor Seminar

    "Cooper-like paring and energy gap induced by ion electronic polarizability"

    Presented by Yizhak Yacoby, Racah Institute of Physics, Hebrew University, Israel

    Monday, May 2, 2016, 1:30 pm
    Bldg. 734, ISB Conference Room 201 (upstairs)

    Hosted by: ''Ron Pindak and Ivan Bozovic''

    We propose a model of Cooper-like pairing induced by the large ion polarizabilities of O2- in Bismutates and Cuprates and As3- and Se2- in the iron pnictides*. We show that the electrical potential field induced by a charge carrier contains in its vicinity pockets of negative potential causing charge carriers to attract each other. Using this model we calculate the approximate pairing and gap energies showing they are compatible with the gap energies measured in high-Tc superconductors. Furthermore we show that the isotope effect, coherence length, and the gap energy dependence on doping are consistent with those observed in high-Tc systems. * Work done in collaboration with Yakov Girshberg

  219. Nuclear Theory/RIKEN Seminar

    "Going with the flow: sign problem, Lefschetz thimbles and beyond"

    Presented by Gokce Basar, University of Maryland

    Friday, April 29, 2016, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: '''Soeren Schlichting'''

    Monte Carlo method, a robust way of studying field theories and many body systems, suffers from the sign problem when the action is complex. This includes an important set of problems such as most field theories, including QCD, and strong correlated electronic systems at finite density, as well as computation of real time quantities like transport coefficients. I will show that lifting the path integration to a complex manifold provides a way to ameliorate the sign problem, and introduce a new algorithm for carrying on such a computation. I will give some quantum mechanical examples with severe sign problems, including finite density of fermions and real time observables where Monte Carlo simulations can be profitably performed by this method. Finally I will discuss the 3+1d Bose gas with nonzero chemical potential.

  220. Particle Physics Seminar

    "Higgs' invisible branching fraction at the LHC"

    Presented by Tae Min Hong, University of Pennsylvania

    Thursday, April 28, 2016, 3 pm
    Small Seminar Room, Bldg. 510

    Hosted by: 'Michael Begel'

    Does the Higgs have a large invisible branching fraction? Two approaches are presented. The first is an indirect constraint of the invisible branching fraction using precision Higgs couplings measurements. The second is a direct search of invisible decays. In particular, I will discuss in detail two of ATLAS's results: the H -> WW in VBF, which is one of the strongest inputs for the couplings and the evidence for VBF Higgs production, and the H -> invisible in VBF, which gives the strongest direct limit. Comparisons with CMS's results are made.

  221. RIKEN Lunch Seminar

    "Solving QCD2"

    Presented by Alexei Tsvelik, BNL

    Thursday, April 28, 2016, 12:30 pm
    Building 510, Room 2-160

    Hosted by: 'Daniel Pitonyak'

    We study a (1+1)-dimensional version of the famous Nambu-Jona-Lasinio model of Quantum Chromodynamics (QCD2) both at zero and finite chemical potential. We use non- perturbative techniques (non-Abelian bosonization and Truncated Conformal Space Approach). At zero chemical potential we describe a formation of fermion three-quark (nucleons and ?-baryons) and boson (two-quark mesons, six-quark deuterons) bound states and also a formation of a topo- logically nontrivial phase. When the chemical potential exceeds the critical value, the model has a rich phase diagram which includes phases with density wave and superfluid quasi-long-range (QLR) order and also a phase of a baryon Tomonaga-Luttinger liquid (strange metal). The QLR order results as a condensation of scalar mesons (the density wave) or six-quark bound states (deuterons).

  222. HET/RIKEN Seminar

    "Heavy Higgs Resonance Dip"

    Presented by Sunghoon Jung, SLAC

    Wednesday, April 27, 2016, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: ''Cen Zhang''

    We discuss overlooked resonance shapes of heavy Higgs bosons that arise from the resonance-continuum interference with a complex phase. They include pure resonance dips and nothingness. We derive conditions under which they are produced and we modify narrow width approximation suitable for them. We then discuss how MSSM heavy Higgs searches at the LHC can be challenged and changed.

  223. Physics Colloquium

    "Neutrino Physics and Mass from Cosmology"

    Presented by Marilena Loverde, Stony Brook University

    Tuesday, April 26, 2016, 3:30 pm
    Large Seminar Room, Bldg. 510

    Hosted by: 'Robert Pisarski'

    Cosmic background neutrinos are nearly as abundant as cosmic microwave background photons, but their mass, which determines the strength of their gravitational clustering, is unknown. Neutrino oscillation data gives a strict lower limit on neutrino mass, while cosmological datasets provide the most stringent upper limit. Even if the neutrino masses are the minimum required by oscillation data, their gravitational effects on structure formation will nevertheless be detectable in — and in fact required to explain — data within the next decade. I will discuss the physical effects of the cosmic neutrino background on structure formation and present a new signature that may be used to measure neutrino mass with large galaxy surveys.

  224. Center for Functional Nanomaterials Seminar

    "Disordered water phases from ambient to ultrahigh pressure"

    Presented by Roberto Car, Princeton University

    Tuesday, April 26, 2016, 11 am
    CFN, Bldg. 735, 2nd Fl. Seminar Room

    Hosted by: 'Deyu Lu'

    Center for Functional Nanomaterials Special Seminar Disordered water phases from ambient to ultrahigh pressure Roberto Car Princeton University Tuesday, April 26, 2016 11:00 a.m. CFN, Bldg. 735, 2nd floor Seminar Room The unusual properties of water, including the thermodynamic anomalies of the liquid, the existence of more than one amorphous ice form, and the abnormal mobilities of the water ions, derive from the tetrahedral network of hydrogen bonds that hold the molecules together. Under applied pressure the topology of the network changes but local tetrahedrality is preserved as the system explores a variety of different phases until at extreme pressure the molecules dissociate into ions and the hydrogen bonds collapse. Modern ab-initio simulations provide a unifying picture of these processes. In this talk, I will review recent progress in these studies stressing connections between theory, simulation, and experiment. Bio Roberto Car of Princeton University is Ralph W. Dornte professor for chemistry with a simultaneous appointment at the Material Sciences Institute of the university. He is a professor in the Theory Department, of the Fritz Haber Institute of the Max Planck Society. His research focus is theory and numerical simulation (classical and quantum) of condensed and molecular systems. He studied physics and attained a doctorate in 1971 in nuclear technology at the Politecnico di Milano. After being professor for physics at SISSA in Trieste (1984-1991), and at University of Geneva (1991-1999) he joined Princeton University in 1999. In 2007, a birthday symposium was held at ICTP. He received the Aneesur Rahman prize in computational physics. The Aneesur Rahman Prize is the highest honor given by the American Physical Society for work in computational physics.

  225. C-AD Accelerator Physics Seminar

    Presented by Malek Haj Tahar, BNL

    Friday, April 22, 2016, 4 pm
    Large Conference Room, Bldg. 911B, Rm. A202

    "The problem of nuclear waste continues to raise lots of concerns of whether the nuclear power should continue when the issue of how to deal with its waste has not yet been resolved. After reviewing the history of the nuclear waste problem in the United States of America and other countries, the question of how to remediate this problem is tackled and several options discussed. The focus is on the Accelerator Driven System option, a hybrid technique combining a particle accelerator with a subcritical core. The scope includes technical considerations from the proton accelerator and up to the reactor core."

  226. Nuclear Theory/RIKEN seminar

    "A higher spin theory of neutral excitations of fractional quantum Hall fluids"

    Presented by Dam T. Son, University of Chicago

    Friday, April 22, 2016, 11 am
    Small Seminar Room, Bldg. 510

    Hosted by: '''Soeren Schlichting'''

  227. Particle Physics Seminar

    "New constraints on cosmic inflation from the Keck Array"

    Presented by Chris Sheehy, University of Chicago

    Thursday, April 21, 2016, 3 pm
    Small Seminar Room, Bldg. 510

    Hosted by: 'Anze Slosar'

    The Keck Array, part of the BICEP/Keck program of small aperture cosmic microwave background (CMB) telescopes, is currently taking data at the South Pole in Antarctica. The goal of the BICEP/Keck program is to detect the B-mode pattern in the CMB's polarized anisotropy that would be a signature of cosmic inflation, or, barring a detection, to set upper limits that rule out some of the most favored theoretical scenarios. Previous results from BICEP2 and the Keck Array that detected B-modes at high significance consisted of data taken only at 150 GHz, and which could therefore not conclusively distinguish between a cosmological vs. galactic origin for the signal. A subsequent joint analysis with the Planck satellite collaboration that invoked their comparatively noisy but multifrequency maps revealed a large component of the signal to be from polarized thermal emission of galactic dust. In this talk, I will present the results from the first year of observations with Keck's new 95 GHz receivers. These results set the most stringent limits on cosmic inflation to date and mark the point at which CMB polarization now constrains inflation better than any other data set.

  228. RIKEN Lunch Seminar

    "Color fluctuation phenomena in high energy hadron & photon-A collisions"

    Presented by Mark Strikman, Penn State University

    Thursday, April 21, 2016, 12:30 pm
    Building 510, Room 2-160

    Hosted by: ''Daniel Pitonyak''

    Compositeness of the bound states and the Lorentz slowing down of high energy interactions in QED and QCD lead to emergence of new coherent phenomena. We focus on the phenomena related to the fluctuations of the strength of interaction (color fluctuations phenomena). First we consider gross violations of the Glauber model for centrality dependence of production of the leading jets in pA scattering predicted earlier within QCD and recent evidence for this phenomenon from the studies of hard pA collisions at the LHC and dAu collisions at RHIC. Color fluctuations also explain a large suppression of the cross section of coherent vector meson photoproduction as compared to the Glauber model observed recently in the ultraperipheral collisions at LHC. We outline perspectives of future studies of the color fluctuation phenomenon in ultraperipheral heavy ion collisions at the LHC and electron - nucleus colliders.

  229. Joint BNL/YITP HET Seminar

    "Progress and Results with the GENEVA Monte Carlo"

    Presented by Christian Bauer, LBNL

    Wednesday, April 20, 2016, 2:30 pm
    YITP (SBU)

  230. Environmental & Climate Sciences Department Seminar

    "Improved Tandem Measurement Techniques for Gas Phase Nanoparticle Analysis"

    Presented by Vivek Rawat, University of Minnesota

    Wednesday, April 20, 2016, 11 am
    Conference Room, Bldg 815E

    Hosted by: 'Jian Wang'

    Non-spherical, chemically inhomogeneous nanoparticles are encountered in a number of natural and engineered environments, including combustion systems, reactors used in gas-phase materials synthesis, and in ambient air. To better characterize these complex nanoparticles, tandem measurement techniques are well suited, in which analytes are characterized by two orthogonal properties (e.g. size and mass). Tandem measurement techniques have been applied in a number of situations; however, there are still a considerable number of fundamental developments needed to advance these approaches. Specifically, new instrument combinations (with existing instruments) and appropriate data inversion routines need to be developed to determine combined two-dimensional mass-size distribution functions, pure mass distribution and for mobility-mass analysis for sub 2-nm clusters (ions). With this motivation, we first develop and apply a data inversion routine to determine the number based size-mass distribution function (two dimensional distribution) from tandem differential mobility analyzer-aerosol particle mass analyzer (DMA-APM) measurements, while correcting for multiple charging, instrument transfer functions and other system efficiencies. This two dimensional distribution can be used to calculate the number based size distribution or the mass based size distribution. We employ this technique to analyze various spherical and non-spherical nanoparticles and examine the validity of this approach by comparing the calculated size distribution functions and mass concentrations with direct measurements of these quantities. In a second study, we utilize a transversal modulation ion mobility spectrometer (TMIMS) coupled with a mass spectrometer (MS) to study vapor dopant induced mobility shifts of sub 2 nm ion clusters. Isopropanol vapor is introduced into the TMIMS, shifting the mobilities of ions to varying extents depending on ion surface chemistry, which provides an improved separa

  231. Physics Colloquium

    "The nature of the composite fermion in quantum Hall liquids"

    Presented by Dam Thanh Son, University of Chicago

    Tuesday, April 19, 2016, 3:30 pm
    Large Seminar Room, Bldg. 510

    Hosted by: 'Robert Pisarski'

    The quantum Hall liquids are some of the most nontrivial strongly interacting states of matter. Experiments have established the existence of the composite fermion as an effective degree of freedom of quantum Hall systems near half filling. A long-standing problem of existing theories of the composite fermion is the lack of particle-hole symmetry of the lowest Landau level. I will describe how the particle-hole symmetry took a central role in recent theoretical discussions of the fractional quantum Hall effect; in particular, how a recent synthesis, motivated by the physics of graphene and topological insulators, has lead to a new understanding of the low-energy quasiparticle of the half-filled Landau level. According to the new picture, the composite fermion is a Dirac particle, with a gauge but non-Chern-Simons interaction. Distinctive consequences of the new proposal are outlined.

  232. Nuclear Theory/RIKEN seminar

    "Vorticular fluid and Lambda Polarization in High-energy Heavy-ion Collisions"

    Presented by Xin-Nian Wang, LBNL/CCNU

    Friday, April 15, 2016, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: ''Soeren Schlichting''

    The strongly coupled quark-gluon plasma created in high-energy heavy-ion collisions has rich vortical structures that are caused by global total orbital angular momentum and transverse evolution of longitudinal flow. Fermions (quarks in sQGP phase and baryons in the hadronic phase) in such a vorticular fluid are naturally polarized due to spin-orbital. I will discuss both local and global quark polarization and how one can use the lambda polarization in the final state to study the vortical structure and constrain the transport properties of sQGP.

  233. HET Lunch Discussions

    "Agravity: an adimensional theory of gravity"

    Presented by Pier Paolo Giardino, BNL

    Friday, April 15, 2016, 12:15 pm
    Building 510, Room 2-160

    Hosted by: 'Christoph Lehner'

  234. Particle Physics Seminar

    "Nuclear reactor antineutrinos, hard to detect but with a traceable lineage."

    Presented by Alejandro Sonzogni, BNL

    Thursday, April 14, 2016, 3 pm
    Small Seminar Room, Bldg. 510

    Hosted by: 'Xin Qian'

    The antineutrino spectrum from nuclear reactors can be calculated using the so-called "summation method", which requires precise knowledge of the fission yield and decay properties of the about 1000 radionuclides produced in a reactor following the fission of the actinide fuel. Alternatively, the antineutrino spectra can also be calculated using the "conversion method", which relies on precisely measured electron spectra. We have recently updated both decay and fission data that enabled us to a) identify the nuclides that contributes the most at different energy regions, b) derive a systematic of the IBD cross section integrated spectra as function of Z and A, similar to that of beta-delayed neutrons, c) asses if an excess of antineutrinos observed at around 5.5 MeV can be discerned using nuclear data.

  235. Center for Functional Nanomaterials Seminar

    "Sub-50 fs Photophysics and Photochemistry of Transition Metal Complexes and Polyhalomethanes"

    Presented by Sergey Mikhailovich Matveev, Bowling Green State University

    Monday, April 11, 2016, 1:30 pm
    CFN, Bldg. 735, 1st floor conf. rm. A

    Hosted by: 'Mircea Cotlet'

    Lowest energy electronic excited states (LEES) in transition metal complexes are the states most relevant for practical photophysical and photochemical processes. We investigated relaxation dynamic of two systems – copper chloride dianion with strong Jahn-Teller effect and hexabromoiridate dianion with spin-spin coupling, utilizing 2000 nm near-IR femtosecond (100 fs) pump-probe spectroscopy. In both systems, the Franc- Condon excited states of the transition metal complexes undergo internal conversion to the ground electronic states, but with significantly different lifetimes (55 fs and 360 ps, respectively), despite the fact that the metal-centered states are separated by the same energy gap (~5000 wavenumbers) from the respective ground state. This difference is explained by presence of a conical intersection between the first excited electronic and the ground states in the Cu(II) system due to strong Jahn-Teller linear distortion whereas the involved potential energy surfaces for the Ir(IV) complex are nested directly one above another. Another project under consideration is the ultrafast mechanisms of polyhalomethanes on the example of diiodomethane. This molecule has a tractable number of degrees of freedom, and, therefore, has served in literature as a model system for bond dissociation processes in both gas and condensed phases. In this work we implemented the state-of-the-art ultrafast (~35 fs) transient absorption experiment (supported by the most accurate multireference quantum chemical methods) to understand the UV photodissociation mechanism of methylene iodide molecules. We discovered previously unsuspected photochemical pathway in the UV photochemistry of methylene iodide, in which electronically excited molecules, rather than simply dissociate, undergo direct ~50-fs isomerization through a conical intersection into isomeric species. Host: Mircea Cotlet

  236. HET/PARTICLE/RBRC Seminar

    ""Recent Highlights from CMS and from the 13 TeV run at the LHC""

    Presented by Albert de Roeck, CERN/University of Antwerp

    Friday, April 8, 2016, 2 pm
    Large Seminar Room, Bldg. 510

    Hosted by: '''Amarjit Soni'''

  237. Particle Physics Seminar

    "Dark Matter Search Results from PICO-2L"

    Presented by Chanpreet Amole, Queen's University, SNOLAB

    Thursday, April 7, 2016, 10 am
    Small Seminar Room, Bldg. 510

    Hosted by: 'Xin Qian'

    New data are reported from a second run of the 2-liter PICO-2L C3F8 bubble chamber with a total exposure of 129 kg-days at a thermodynamic threshold energy of 3.3 keV. These data show that measures taken to control particulate con-tamination in the superheated fluid resulted in the absence of the anomalous back-ground events observed in the first run of this bubble chamber. One single nuclear-recoil event was observed in the data, consistent both with the predicted background rate from neutrons and with the observed rate of unambiguous multiple-bubble neutron scattering events. The chamber exhibits the same excellent electron-recoil and alpha decay rejection as was previously reported. These data provide the most stringent direct detection constraints on WIMP- proton spin-dependent scattering to date for WIMP masses < 50 GeV/c2.

  238. 'Science on Tap'

    "A Conversation With Paul Sorensen"

    Presented by Paul Sorensen, Brookhaven Lab

    Tuesday, April 5, 2016, 7 pm
    Stony Brook Yacht Club

    Hosted by: ''Alan Alda Center for Communicating Science''

    Paul Sorensen recreates the birth of the universe, smashing the nuclei of gold atoms together with such extreme violence that they melt into a cosmic soup that hasn't existed since the universe was a microsecond old. In conversation with Stony Brook University's journalism professor, Steven Reiner, Sorensen will bring to vivid life the epic endeavor to create in Brookhaven National Laboratory's atom smasher minute specks of the hottest matter ever made on Earth, and tell us what these fleeting fireballs may reveal about the origin of everything, including ourselves.

  239. Physics Colloquium

    "Hunting for WIMPs in Panda Land"

    Presented by Xiangdong Ji, University of Maryland

    Tuesday, April 5, 2016, 3:30 pm
    Large Seminar Room, Bldg. 510

    Hosted by: ''''Robert Pisarski''''

    Weakly interacting massive particles (WIMPs), with properties similar to those of a heavy neutrino, have been a leading candidate for the 27% dark matter in the Universe. Direct detection experiments by detecting the nuclear recoils from elastic scattering of WIMPs with atomic nuclei have made huge strides in the last decade, improving the sensitivity by some five orders of magnitude. In this talk, I will describe the results from an adventure of searching for WIMPs with the PandaX, currently the most sensitive running liquid xenon dark matter detector, in the world's deep underground lab in the high mountains, western China.

  240. Nuclear Theory/RIKEN seminar

    "Studying Nucleons in Soliton Models"

    Presented by Song Shu, Stonybrook University

    Friday, April 1, 2016, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: ''Soeren Schlichting''

    Both chiral solitons and confined solitons are discussed at finite temperatures and densities in effective models. Based on the solitons the nucleon properties are studied in thermal medium. The nucleon mass in medium is carefully calculated. It is showed that the chiral solitons could even survive after the chiral phase transition, while confined solitons collapse after the system is deconfined.

  241. Particle Physics Seminar

    "Milicharge: A Proposal"

    Presented by Ben Kaplan, New York University

    Thursday, March 31, 2016, 3 pm
    Small Seminar Room, Bldg. 510

    Hosted by: ''Michael Begel''

    I will present the status of the MilliQan experiment, a milli-charged particle detector we propose to install at LHC P5. The experiment would be commissioned during the next LHC shutdown in a service tunnel ~30m above the CMS interaction point, behind ~15m of rock. I will present the theoretical motivation for building the detector, its proposed experimental design, and the expected sensitivity to milli-charged particles.

  242. RIKEN Lunch Seminar

    "Sphalerons Far From Equilibrium and Associated Phenomena"

    Presented by Mark Mace, Stony Brook University

    Thursday, March 31, 2016, 12:30 pm
    Building 510 Room 2-160

    Hosted by: 'Daniel Pitonyak'

    In this talk, I will present a first computation of sphalerons in the glasma; the highly occupied, weakly coupled gluon dominated pre-equilibrium matter created at early times after an ultra-relativistic heavy ion collisions. The sphaleron transition is a well known ingredient in the generation of anomalous vector current from a strong external magnetic field, the so-called Chiral Magnetic Effect. We perform classical-statistical real-time lattice simulations to study the dynamics of these topological transitions; simplifying our description by employing SU(2) gauge fields and neglecting the longitudinal expansion for this first study. I will show that the non-equilibrium sphaleron transition rate is time dependent and non-Markovian, in addition to being dominant in comparison to the thermal equilibrium sphaleron transition rate. In addition, we can measure the scaling and separation of physical scales in analogy to those from thermal equilibrium, in order to parameterize this rate and understand the approach to equilibrium. I will then demonstrate that it is the magnetic screening length, which we extract non-perturbatively, that controls this rate. Additionally, I will briefly mention studies of related anomalous transport effects that we plan on studying using this first principles classical-statistical real-time lattice technology.

  243. Condensed-Matter Physics & Materials Science Seminar

    "Topological Insulators and Dirac Semimetals - Recent Progress in New Materials"

    Presented by Robert J. Cava, Princeton University

    Thursday, March 31, 2016, 10 am
    Large Seminar Room, Bldg. 510

    Hosted by: ''Peter D. Johnson''

    "New materials give new properties" describes the goal of our solid state chemistry research program. This goal would be much easier to attain if there was a reliable way to predict the stability of an unknown non-molecular solid, then predict what its properties would be, then make it as a real material and then finally test it, but unfortunately that is not the case; establishing such a process is the grand challenge in contemporary solid state chemistry, and so we have to operate differently. Our discussions with experimental and theoretical physicists teach us about current issues in the electronic and magnetic properties of matter, and our chemistry background teaches us how to think about crystal structures and bonding; our work is about trying to put these two cultures together to find new materials. In this talk I will describe some of our recent results in Topological Insulators and Dirac and Weyl Semimetals.

  244. Physics Colloquium

    "Quark-Gluon Plasma: An Old and New Phase of Quantum Matter"

    Presented by Jinfeng Liao, Indiana University

    Tuesday, March 29, 2016, 3:30 pm
    Large Seminar Room, Bldg. 510

    Hosted by: Robert Pisarski

    The use of fire was instrumental for human civilization. Early conception of varied phases of matter as well as transitions among them, perhaps developed from e.g. burning wood and heating water. Those ancient pursuits continue into the modern quest for understanding the structure of matter under extreme conditions: what's the phase of matter when heated to unprecedented temperature? The answer to this question relies upon our understanding of the strong nuclear force, which is described by quantum chromodynamics (QCD). First principle calculations of QCD predict that the normal nuclear matter, when heated to be hot enough, will change into a new phase of matter called the quark-gluon plasma (QGP). In fact, the QGP was an old phase of matter that occupied the early universe shortly after the Big Bang. Today, such primordial droplets of QGP can be re-created repeatedly and measured precisely in relativistic heavy ion collisions (often called the Little Bangs). Remarkable discoveries have been made at the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC) that together reveal the QGP as a nearly perfect quantum liquid with superior opaqueness. We will discuss a number of novel properties of QGP. In particular we will highlight the recent progress on how certain unusual transport phenomena stemming from microscopic chiral anomaly, which is intrinsically quantum mechanical, could manifest themselves in the macroscopic QGP fluid. A very brief survey will be given on the theoretical developments, the experimental search in heavy ion collisions, as well as the recent exciting progress of such physics in Dirac and Weyl semimetals.

  245. HET Lunch Discussions

    "Musings on a 750GeV diphoton Resonance"

    Presented by William J. Marciano, BNL

    Friday, March 25, 2016, 12:15 pm
    Building 510, Room 2-160

    Hosted by: ''Christoph Lehner''

  246. Particle Physics Seminar

    "Exotic BSM Higgs Decays and proposed LHC Benchmarks"

    Presented by Shufang Su

    Thursday, March 24, 2016, 3 pm
    Small Seminar Room, Bldg. 510

    Hosted by: 'Bill Marciano'

  247. Condensed-Matter Physics & Materials Science Seminar

    "Phase transitions in strongly correlated systems from diagrammatic multi-scale methods"

    Presented by Andrey Antipov, University of Michigan

    Thursday, March 24, 2016, 1:30 pm
    Bldg. 734, ISB Conf. Rm. 201 (upstairs)

    Hosted by: ''Alexei Tsvelik''

    The dynamical mean field theory (DMFT) has become the standard tool in describing strongly correlated electron materials. While it captures the quantum dynamics of local fields, it neglects spatial correlations. To describe e.g. anti-ferromagnetism, unconventional superconductivity or frustration a proper treatment of non-local correlations is necessary. Diagrammatic multi-scale approaches offer an elegant option to accomplish this: the difficult correlated part of the system is solved using a non-perturbative many-body method, whereas 'easier', 'weakly correlated' parts of the problem are tackled using a secondary perturbative scheme. Here we employ such a method, the dual fermion approach, to problems of charge and spin ordering in Falicov-Kimball and Hubbard models by constructing a systematic diagrammatic extension on top of DMFT. Near the critical point model we study the interplay between charge and spin excitations and long-range fluctuations. We show that such multi-scale approach is indeed capable of capturing the non mean-field nature of the critical point of the lattice model and correctly describes the transition to mean-field like behavior as the number of spatial dimensions increases. Our numerical method is available as a freely distributed open-source code.

  248. Special RIKEN/HET Seminar

    "Axion Phenomenology from Unquenched Lattice QCD"

    Presented by Guido Martinelli, Rome University

    Thursday, March 24, 2016, 11 am
    Large Seminar Room, Bldg. 510

    Hosted by: '''Hiroshi Oki'''

    We investigate the topological properties of Nf = 2 + 1 QCD with physical quark masses, both at zero and finite temperature. At zero temperature both finite size and finite cut-off effects have been studied by comparing the continuum extrapolated results for the topological susceptibility χ with the predictions from chiral perturbation theory. At finite temperature, we explore a region going from Tc up to around 4Tc, where continuum extrapolated results for the topological susceptibility and for the fourth moment of the topological charge distribution are obtained. While the fourth moment converges to the dilute instanton gas prediction the topological susceptibility differs strongly both in the size and in the temperature dependence. This results in a shift of the axion dark matter window of almost one order of magnitude with respect to the instanton computation.

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