BNL Home
October 2017
Sunday Monday Tuesday Wednesday Thursday Friday Saturday

1

  1. No events scheduled

2

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3

  1. Nuclear Physics Seminar

    11 am, Small Seminar Room, Bldg. 510

    Hosted by: 'Jiangyong Jia'

    In recent years, there have been rapid progresses in our understanding of the event-by-event flow fluctuation, which provides direct insight into the fluctuations in the initial geometry. I will start my talk by briefly discussing the flow (collectivity) and its fluctuation in small systems pp and p+Pb, using the newly-proposed subevent cumulant method, which is able to suppress the non-flow background effectively. I will show there is significant fluctuation of elliptic flow $v_2$ in pp and non-Gaussian fluctuation of triangular flow $v_3$ in p+Pb. Moving from small to large systems, STAR collaboration recently has shown different behaviors of cumulant $c_2\{4\}$ between Au+Au and U+U in ultra-central collisions, which is believed to support the different geometry fluctuations. By presenting the newest ATLAS flow measurements in ultra-central collisions, together with detailed MC Glauber studies, I will explain why sign change of $c_2\{4\}$ is observed and its implications. In the end, I will go back to small systems and discuss the potential impact of centrality resolution on pp flow measurements.

4

  1. HET Seminar

    2 pm, Small Seminar Room, Bldg. 510

    Hosted by: ''Sally Dawson''

    Measurements of Higgs production and decays have revealed that most of the mass of the weak gauge bosons is due to the 125 GeV Higgs. Similarly, we know that the Higgs is at least partially responsible for giving mass to the top and bottom quarks and the tau lepton. Much less is known about the origin of mass for the first two generations. In this talk, I will discuss a framework in which the first and second generation masses originate from a second source of electroweak symmetry breaking and outline the phenomenological implications.

5

  1. No events scheduled

6

  1. HET Lunch Discussions

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

    Hosted by: 'Christoph Lehner'

7

  1. No events scheduled

8

  1. No events scheduled

9

10

  1. No events scheduled

11

  1. Particle Physics Seminar

    1:30 pm, Stony Brook

    Hosted by: '''Neelima Sehgal'''

12

  1. Nuclear Theory/RIKEN Seminar

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

    Hosted by: 'Chun Shen'

    The Quark Gluon Plasma (QGP), nature's first and most perfect liquid, has been successfully reproduced in heavy-ion collisions at RHIC and the LHC. The dynamics of the QGP can be well described by relativistic viscous hydrodynamics, allowing for precise comparisons to experimental data in order to extract the properties of the QGP. While a small shear viscosity is well-established, questions still remain regarding the precise initial state, the temperature dependence of viscosity, the smallest system that displays QGP-like properties, and the equation of state at large densities. In this talk, the various flow harmonic observables are analyzed to help answer these remaining questions.

13

  1. No events scheduled

14

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15

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16

  1. Condensed-Matter Physics & Materials Science Seminar

    1:30 pm, Bldg. 480, Conference Room

    Hosted by: ''Myung-Geun Han''

    Topological structures in functional materials, such as domain walls and skyrmions, see increased attention due to their properties that can be completely different from that of the parent bulk material [1]. I will discuss recent results on multiferroic phase boundaries, domain walls in BiFeO3 [2, 3, 4, 5, 6] using SPM, TEM and ab-initio theory, and discuss future prospects [7]. References [1] J. Seidel (ed.), Topological structures in ferroic materials: domain walls, skyrmions and vortices, ISBN: 978-3-319-25299-5, Springer, Berlin (2016) [2] P. Sharma, et al., Scientific Reports 6, 32347 (2016) [3] P. Sharma, et al., Advanced Electronic Materials 2, 1600283 (2016) [3] J. Seidel, et al., Advanced Materials 26, 4376 (2014) [4] Y. Heo, et al., Advanced Materials 26, 7568 (2014) [5] Y. Heo et al., ACS Nano, DOI: 10.1021/acsnano.6b07869 (2017) [6] P. Sharma, et al., Advanced Materials Interfaces 3, 1600033 (2016) [7] J. Seidel, Nature Nanotechnology 10, 190 (2015)

  2. Particle Physics Seminar

    2 pm, Small Seminar Room, Bldg. 510

    Hosted by: 'Xin Qian'

    Researchers at IHEP, Beijing have conceived a new concept of MCP-PMT several years ago. The small MCP (Microchannel Plate) units replace the bulky Dynode chain in the tranditional large PMTs for better photoelectron detection. After three years R&D, a number of 8 inch prototypes were produced and their performance was carefully tested at IHEP in 2013 by using the MCP-PMT evaluation system built at IHEP. The 20 inch prototypes were followed in 2014, and its' performance were improving a lot in 2015. Compensating the PMT performances with fiducially volume convert all specifications to cost, radioactivity, dark noise, TTS, the JUNO ordered 15000 pic 20-inch MCP-PMT from the NNVT in Dec.2015. In 2016, the MCP-PMT collaboration group finished to build the mass production line in Nanjing at the end of 2016, and finished the batch test system in the same place within 100 days at the beginning of 2017. From 2017 to 2019, all the 20-inch MCP-PMT will be produced and tested one by one in NNVT for JUNO. This presentation will talk about the R&D process and mass production, batch test result of the first 2K pieces of MCP-PMT prototypes for JUNO.

17

  1. No events scheduled

18

  1. HET Seminar

    2 pm, Small Seminar Room, Bldg. 510

    Hosted by: '''Mattia Bruno'''

19

  1. Environmental & Climate Sciences Department Seminar

    11 am, Conference Room Bldg 815E

    Hosted by: 'Steve Schwartz'

    Airborne particles are ubiquitous components of our atmosphere, originating from a variety of natural and anthropogenic sources, exhibiting a wide range of physical properties, and contributing in multiple ways to regional air quality as well as regional-to-global-scale climate. Most remain in the atmosphere for a week or less, but can traverse oceans or continents in that time, carrying nutrients or disease vectors in some cases. Bright aerosols reflect sunlight, and can cool the surface; light-absorbing particles can heat the atmosphere, suppressing cloud formation or mediating larger-scale circulations. In most cases, particles are required to collect water vapor as the initial step in cloud formation, so their presence (or absence) and their hygroscopic or hydrophilic properties can affect cloud occurrence, structure, and ability to precipitate. Grasping the scope and nature of aerosol environmental impacts requires understanding microphysical-to-global scale processes, operating on timescales from minutes to days or longer. Satellites are the primary source of observations on kilometer-to-global scales. Spacecraft observations are complemented by suborbital platforms: aircraft in situ measurements and surface-based instrument networks that operate on smaller spatial scales, some on shorter timescales. Numerical models play a third key role in this work — providing a synthesis of current physical understanding with the aggregate of measurements, and allowing for some predictive capability. This presentation will focus on what we can say about aerosol amount and type from space. Constraining particle "type" is at present the leading challenge for satellite aerosol remote sensing. We will review recent advances and future prospects, including the strengths and limitations of available approaches, and current work toward better integrating measurements with models to create a clearer picture of aerosol environmental impacts, globally.

  2. RIKEN Lunch Seminar

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

    Hosted by: 'Enrico Rinaldi'

    The nucleon axial form factor is a dominant contribution to systematic uncertainties in neutrino oscillation studies. The most commonly used model parametrization of the axial form factor has uncontrolled and underestimated systematic errors. First-principles computations from lattice QCD have the potential to control theory errors by disentangling the effects of nuclear corrections from the nucleon amplitudes. In this talk, I discuss fits to the axial form factor with deuterium bubble chamber data using the model-independent $z$ expansion parameterization. I then present preliminary results for a blinded lattice QCD calculation of the nucleon axial charge $g_A$ with physical light quark masses. This calculation is being done with the Highly Improved Staggered Quark (HISQ) action and 2+1+1 flavors of sea quarks.

  3. Particle Physics Seminar

    3 pm, Small Seminar Room, Bldg. 510

    Hosted by: 'Alessandro Tricoli'

    Recent measurements of the Higgs boson properties in the four lepton channel for 36.1 fb-1 of proton—proton collisions at 13 TeV using the ATLAS detector will be presented. The measurements include the Higgs boson mass as well as inclusive, fiducial and differential cross sections and, constraints on Higgs boson production couplings. The results are interpreted within the Standard Model and various extensions.

20

  1. Nuclear Theory/RIKEN Seminar

    2 pm, Small Seminar Room, Bldg. 510

    Hosted by: ''Chun Shen''

    In the so-called isobar parametrization the three-particle states are populated via an interacting two-particle system (resonant or non-resonant), and a spectator. Using this parametrization, we derive the isobar-spectator interaction such that the three-body Unitarity is ensured exactly. In the first part of my talk I will show the major steps of this derivation. (arXiv:1706.06118) The second part of the talk will be dedicated to the finite-volume implementation of the framework (arXiv:1709.08222). Imaginary parts in the infinite volume, dictated by Unitarity, determine the dominant power-law finite volume effects to ensure the correct 3-body quantization condition. Furthermore, various building blocks of the 3->3 amplitude in the finite volume can become singular. However, when all contributions are summed-up, only genuine 3-body singularities remain. I will demonstrate the corresponding cancellation mechanisms explicitly for the simplified case of only one S-wave isobar.

  2. Condensed-Matter Physics & Materials Science Seminar

    3 pm, ISB Bldg. 734 Conf. Rm. 201 (upstairs)

    Hosted by: '''Igor Zaliznyak'''

    Orbital and spin degrees of freedom in heavy transition metal compounds can be locked into each other due to strong spin-orbit coupling. The magnetism in this case is described by an effective total angular momentum jeff=1/2 rather than usual spin angular momentum. Furthermore, these jeff=1/2 moments residing on a honeycomb lattice can be coupled through bond-dependent Kitaev interactions. Magnetic properties of some honeycomb lattice iridates, such as Na2IrO3 and Li2IrO3 have been extensively investigated to examine whether Kitaev quantum spin liquid is realized in these compounds. However, the applicability of the jeff=1/2 local moment model in real materials have not been critically scrutinized experimentally. A combination of x-ray absorption spectroscopy, x-ray diffraction, and resonant inelastic x-ray scattering experiments on a honeycomb lattice Li2IrO3 reveals that the jeff=1/2 picture breaks down under high pressure, and electrons take on more itinerant character under this condition.

21

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22

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23

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24

  1. OCT

    24

    Tuesday

    Nuclear Physics Seminar

    11 am, Small Seminar Room, Bldg. 510

    Tuesday, October 24, 2017, 11:00 am

    Hosted by: 'Bjoern Schenke'

    The observation of charge separation induced by the Chiral Magnetic Effect (CME), could provide crucial insights on anomalous transport and the interplay of chiral symmetry restoration, axial anomaly, and gluonic topology in the Quark Gluon Plasma (QGP) produced in heavy ion collisions. I will discuss recent differential charge separation measurements,for p(d)+Au, Au(Cu)+Au and U+U, with a correlator specifically designed to give discernible responses to CME-driven charge separation and non-CME backgrounds. Measurements which span the beam energy range Root_s = 19.5 - 200 GeV will be presented. The d(p)+Au results are observed to be consistent with the reduced magnetic field strength and the essentially random B-field orientations expected in these collisions. In contrast, the Au(Cu)+Au and U+U measurements validate the presence of CME-driven charge separation quantified by the Fourier dipole coefficient a1. Ongoing attempts for CME-signal quantification, as well as implications for the upcoming RHIC isobar run, will be discussed as well.

  2. OCT

    24

    Tuesday

    Physics Colloquium

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

    Tuesday, October 24, 2017, 3:30 pm

    Hosted by: 'Peter Petreczky'

    On August 17, 2017 the merger of two neutron stars was detected in the form of gravitational-waves by LIGO/Virgo. As a result of over a decade long preparation for multimessenger observations the event was also seen electromagnetically across the full spectrum. The history and future of the multimessenger effort using gravitational-waves will be discussed from an instrumentalist viewpoint.

25

  1. OCT

    25

    Wednesday

    Condensed-Matter Physics & Materials Science Seminar

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

    Wednesday, October 25, 2017, 1:30 pm

    Hosted by: '''Cedomir Petrovic'''

    Progress in the widespread adoption of all solid heat-to-electricity technologies has largely been hindered by the absence of suitable thermoelectric materials. In pursuit for new thermoelectrics recent advances in large-scale deployment of first principles calculations could be useful in identifying new promising material systems. However, the need to predict electron and phonon transport properties with sufficient accuracy renders direct assessment of the thermoelectric figure of merit (zT) for large numbers of systems unfeasible. This is true even in the case of relatively simple semiconductor materials, which could be described by the computationally inexpensive single particle theories such as density functional theory (DFT). While the state-of-the-art DFT based approaches to charge carrier and heat transport of semiconductors can deliver desired accuracy, they are currently limited to relatively simple chemistries and/or case-by-case studies. In this talk I will discuss integrated theory-computation-experiment efforts in developing a robust set of material descriptors that: (1) are rooted in the Boltzmann transport theory, but do not rely on classic and largely inapplicable constant relaxation time or constant mean free path approximations, (2) are computationally tractable allowing material searches across large chemical spaces, and (3) are sufficiently accurate to provide reliable predictions. Our approach is demonstrated to correctly identify known thermoelectric materials1 and reliably suggest new and promising candidate semiconductors.2 At the end, I will review successes and failures in our quest for new thermoelectrics, and discuss dopability of semiconductors as the critical outstanding challenge in achieving high zT materials. 1. Yan, P. Gorai, B. Ortiz, S. Miller, S. A. Barnett, T. Mason, V. Stevanovic, and E. S. Toberer, "Material descriptors for thermoelectric performance", Energy Environ. Sci. 2. P. Gorai, V. Stevanovic, and E. Tobe

26

  1. OCT

    26

    Thursday

    RIKEN Lunch Seminar

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

    Thursday, October 26, 2017, 12:30 pm

    Hosted by: ''Hiromichi Nishimura''

    Quarkonium can be used as a probe of quark-gluon plasma (QGP) in heavy ion collisions. The production process is complicated by several factors: plasma screening effect, in-medium dissociation and recombination, cold nuclear matter effect and feed-down contributions. In this talk, I will present a set of Boltzmann transport equations that govern the in-medium evolution of the heavy quark and quarkonium system. The dissociation and recombination rates are calculated from potential non-relativistic QCD at leading order. I will explain how the system reaches equilibrium in a QGP box and show how the system evolves under a boost invariant longitudinal expansion. I will argue that the angular distribution of quarkonium probes the stages at which recombination occurs. The presented framework will be extended in future work to include other factors influencing quarkonium production.

  2. OCT

    26

    Thursday

    Particle Physics Seminar

    3 pm, Small Seminar Room, Bldg. 510

    Thursday, October 26, 2017, 3:00 pm

    Hosted by: 'Xin Qian'

    Coherent elastic neutrino-nucleus scattering (CEvNS) is a process in which a neutrino scatters off an entire nucleus at low momentum transfer, and for which the observable signature is a low-energy nuclear recoil. It represents a background for direct dark matter detection experiments, as well as a possible signal for astrophysical neutrinos. Furthermore, because the process is cleanly predicted in the Standard Model, a measurement is sensitive to beyond-the-Standard-Model physics, such as non-standard interactions of neutrinos. The process was first predicted in 1973. It was measured for the first time by the COHERENT collaboration using the high-quality source of pion-decay-at-rest neutrinos from the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory and a CsI[Na] scintillator detector. This talk will describe COHERENT's recent 6.7-sigma measurement of CEvNS, the status and plans of COHERENT's suite of detectors at the SNS, and future physics reach.

27

  1. OCT

    27

    Friday

    Particle Physics Seminar

    10 am, Small Seminar Room, Bldg. 510

    Friday, October 27, 2017, 10:00 am

    Hosted by: ''Alessandro Tricoli''

    There is an extensive, on-going dark matter search program at the LHC that explores several different types of possible interactions between WIMP-like dark matter and standard model particles. The dark matter searches at the LHC are complementary, and in case of certain models, significantly more sensitive than the direct and indirect dark matter searches. In this talk I will discuss several key dark matter searches being pursued by the CMS collaboration. These cover a wide variety of final states in which dark matter particles are produced in association with one or more energetic, visible objects in the detector resulting in 'MET+X' signatures. Furthermore, I will also discuss the constraints set on dark matter interactions by certain resonance searches.

28

  1. No events scheduled

29

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30

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31

  1. No events scheduled

  1. OCT

    24

    Tuesday

    Nuclear Physics Seminar

    "To CME or not to CME? Implications of recent charge separation measurements in p(d)+Au, Au(Cu)+Au and U+U collisions for the chiral magnetic effect in heavy ion collisions"

    Presented by Roy Lacey, Stony Brook University

    11 am, Small Seminar Room, Bldg. 510

    Tuesday, October 24, 2017, 11:00 am

    Hosted by: 'Bjoern Schenke'

    The observation of charge separation induced by the Chiral Magnetic Effect (CME), could provide crucial insights on anomalous transport and the interplay of chiral symmetry restoration, axial anomaly, and gluonic topology in the Quark Gluon Plasma (QGP) produced in heavy ion collisions. I will discuss recent differential charge separation measurements,for p(d)+Au, Au(Cu)+Au and U+U, with a correlator specifically designed to give discernible responses to CME-driven charge separation and non-CME backgrounds. Measurements which span the beam energy range Root_s = 19.5 - 200 GeV will be presented. The d(p)+Au results are observed to be consistent with the reduced magnetic field strength and the essentially random B-field orientations expected in these collisions. In contrast, the Au(Cu)+Au and U+U measurements validate the presence of CME-driven charge separation quantified by the Fourier dipole coefficient a1. Ongoing attempts for CME-signal quantification, as well as implications for the upcoming RHIC isobar run, will be discussed as well.

  2. OCT

    24

    Tuesday

    Physics Colloquium

    "The Path Forward in Gravitational-wave astronomy"

    Presented by Zsuzsa Marka, Columbia University

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

    Tuesday, October 24, 2017, 3:30 pm

    Hosted by: 'Peter Petreczky'

    On August 17, 2017 the merger of two neutron stars was detected in the form of gravitational-waves by LIGO/Virgo. As a result of over a decade long preparation for multimessenger observations the event was also seen electromagnetically across the full spectrum. The history and future of the multimessenger effort using gravitational-waves will be discussed from an instrumentalist viewpoint.

  3. OCT

    25

    Wednesday

    Condensed-Matter Physics & Materials Science Seminar

    "Theory and Computation Guided Discovery of New Thermoelectric Materials"

    Presented by Vladan Stevanovic, Colorado School of Mines & National Renewable Energy Laboratory

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

    Wednesday, October 25, 2017, 1:30 pm

    Hosted by: '''Cedomir Petrovic'''

    Progress in the widespread adoption of all solid heat-to-electricity technologies has largely been hindered by the absence of suitable thermoelectric materials. In pursuit for new thermoelectrics recent advances in large-scale deployment of first principles calculations could be useful in identifying new promising material systems. However, the need to predict electron and phonon transport properties with sufficient accuracy renders direct assessment of the thermoelectric figure of merit (zT) for large numbers of systems unfeasible. This is true even in the case of relatively simple semiconductor materials, which could be described by the computationally inexpensive single particle theories such as density functional theory (DFT). While the state-of-the-art DFT based approaches to charge carrier and heat transport of semiconductors can deliver desired accuracy, they are currently limited to relatively simple chemistries and/or case-by-case studies. In this talk I will discuss integrated theory-computation-experiment efforts in developing a robust set of material descriptors that: (1) are rooted in the Boltzmann transport theory, but do not rely on classic and largely inapplicable constant relaxation time or constant mean free path approximations, (2) are computationally tractable allowing material searches across large chemical spaces, and (3) are sufficiently accurate to provide reliable predictions. Our approach is demonstrated to correctly identify known thermoelectric materials1 and reliably suggest new and promising candidate semiconductors.2 At the end, I will review successes and failures in our quest for new thermoelectrics, and discuss dopability of semiconductors as the critical outstanding challenge in achieving high zT materials. 1. Yan, P. Gorai, B. Ortiz, S. Miller, S. A. Barnett, T. Mason, V. Stevanovic, and E. S. Toberer, "Material descriptors for thermoelectric performance", Energy Environ. Sci. 2. P. Gorai, V. Stevanovic, and E. Tobe

  4. OCT

    26

    Thursday

    RIKEN Lunch Seminar

    "Approach to equilibrium of quarkonium in quark-gluon plasma"

    Presented by Xiaojun Yao, BNL

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

    Thursday, October 26, 2017, 12:30 pm

    Hosted by: ''Hiromichi Nishimura''

    Quarkonium can be used as a probe of quark-gluon plasma (QGP) in heavy ion collisions. The production process is complicated by several factors: plasma screening effect, in-medium dissociation and recombination, cold nuclear matter effect and feed-down contributions. In this talk, I will present a set of Boltzmann transport equations that govern the in-medium evolution of the heavy quark and quarkonium system. The dissociation and recombination rates are calculated from potential non-relativistic QCD at leading order. I will explain how the system reaches equilibrium in a QGP box and show how the system evolves under a boost invariant longitudinal expansion. I will argue that the angular distribution of quarkonium probes the stages at which recombination occurs. The presented framework will be extended in future work to include other factors influencing quarkonium production.

  5. OCT

    26

    Thursday

    Particle Physics Seminar

    "Observation of Coherent Elastic Neutrino-Nucleus Scattering by COHERENT"

    Presented by Kate Scholberg, Duke University

    3 pm, Small Seminar Room, Bldg. 510

    Thursday, October 26, 2017, 3:00 pm

    Hosted by: 'Xin Qian'

    Coherent elastic neutrino-nucleus scattering (CEvNS) is a process in which a neutrino scatters off an entire nucleus at low momentum transfer, and for which the observable signature is a low-energy nuclear recoil. It represents a background for direct dark matter detection experiments, as well as a possible signal for astrophysical neutrinos. Furthermore, because the process is cleanly predicted in the Standard Model, a measurement is sensitive to beyond-the-Standard-Model physics, such as non-standard interactions of neutrinos. The process was first predicted in 1973. It was measured for the first time by the COHERENT collaboration using the high-quality source of pion-decay-at-rest neutrinos from the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory and a CsI[Na] scintillator detector. This talk will describe COHERENT's recent 6.7-sigma measurement of CEvNS, the status and plans of COHERENT's suite of detectors at the SNS, and future physics reach.

  6. OCT

    27

    Friday

    Particle Physics Seminar

    "Search for dark matter at the CMS experiment"

    Presented by Adish Vartak, University of California San Diego

    10 am, Small Seminar Room, Bldg. 510

    Friday, October 27, 2017, 10:00 am

    Hosted by: ''Alessandro Tricoli''

    There is an extensive, on-going dark matter search program at the LHC that explores several different types of possible interactions between WIMP-like dark matter and standard model particles. The dark matter searches at the LHC are complementary, and in case of certain models, significantly more sensitive than the direct and indirect dark matter searches. In this talk I will discuss several key dark matter searches being pursued by the CMS collaboration. These cover a wide variety of final states in which dark matter particles are produced in association with one or more energetic, visible objects in the detector resulting in 'MET+X' signatures. Furthermore, I will also discuss the constraints set on dark matter interactions by certain resonance searches.

  7. NOV

    1

    Wednesday

    HET/RIKEN Seminar

    "TBA"

    2 pm, Small Seminar Room, Bldg. 510

    Wednesday, November 1, 2017, 2:00 pm

    Hosted by: 'Sally Dawson'

  8. NOV

    2

    Thursday

    RIKEN Lunch Seminar

    "Rotating Dirac fermion in Magnetic field in 1+2 and 1+3 dimensions"

    Presented by Yizhuang Liu, Stony Brook University

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

    Thursday, November 2, 2017, 12:30 pm

    Hosted by: 'Hiromichi Nishimura'

  9. NOV

    2

    Thursday

    Particle Physics Seminar

    "UCNtau: A magneto-gravitational trap measurement of the free neutron lifetime"

    Presented by Robert Pattie, Los Alamos National Laboratory

    3 pm, Small Seminar Room, Bldg. 510

    Thursday, November 2, 2017, 3:00 pm

    Hosted by: ''Xin Qian''

    The neutron is the simplest nuclear system that can be used to probe the structure of the weak interaction and search for physics Beyond the Standard Model. Measurements of neutron ?-decay observables are sensitive to scalar and tensor interactions in the weak force which are not present in the Standard Model. The lifetime of the neutron ?n is an important parameter for Big-Bang Nucleo-synthesis models, solar fusion models, and absolute neutrino scattering cross-sections, and can be used to test the unitarity of the Cabibbo-Kobayashi-Maskawa quark mixing matrix. Presently, the two typical methods used to measure the neutron lifetime, cold neutron beam measurements and stored ultracold neutron (UCN) measurements, disagree by roughly 4?. This discrepancy motivates the need for new measurements with complementary systematic uncertainties to previous efforts. The UCN? experiment uses an asymmetric magneto-gravitational UCN trap with in situ counting of surviving neutrons to measure the neutron lifetime. Previous bottle experiments confined UCN in a material storage vessel creating a significant correction due to losses resulting from the material UCN interactions. The magnetic and gravitational confinement of the UCN minimizes losses due to material interactions. Additionally, UCN? uses a detection system that is lowered into the storage volume which avoids emptying the surviving UCN into an external detector. This minimizes any possible transport related systematics. This in situ detector also enables counting at various heights in the vessel, which provides information on the trapped UCN energy spectrum, quasi-bound orbits, and possible phase space evolution. I will present the physics motivation for precision neutron physics, a description of the UCN? experiment, the results of data collected during the 2016-2017 accelerator cycle which resulted in a value of τn=877.7±(0.7) stat (+0.3/−0.1) sys in agreement with previous material bottle

  10. NOV

    3

    Friday

    Condensed-Matter Physics & Materials Science Seminar

    "Wandering amongst the Feynamn diagrams"

    Presented by Nikolay Prokofiev, University of Massachusetts-Amherst

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

    Friday, November 3, 2017, 11:00 am

    Hosted by: ''Igor Zaliznyak''

    Feynman diagrams are the most celebrated and powerful tool of theoretical physics usually associated with the analytic approach. I will argue that diagrammatic expansions are also an ideal numerical tool with enormous and yet to be explored potential for solving interacting many-body systems by direct simulation of Feynman diagrams (bare or skeleton) for the proper self-energies and polarization operators up to high order. Though the original series based on are propagators are sign-alternating and often divergent one can determine the answer behind them by using proper series re-summation techniques and working with skeleton diagrams, i.e. by making the entire scheme self-consistent. The bottom line is that the diagrammatic Monte Carlo approach generically solves the computational complexity for interacting fermionic systems. In terms of physical applications, I will disucss results for the Hubbard model, resonant fermi gas at unitarity, and stability of Dirac liquid against strong Coulomb interaction in graphene.

  11. NOV

    3

    Friday

    Nuclear Theory/RIKEN Seminar

    "Proton radius puzzle"

    Presented by Gerald Miller, University of Washington

    2 pm, Small Seminar Room, Bldg. 510

    Friday, November 3, 2017, 2:00 pm

    Hosted by: 'Chun Shen'

  12. NOV

    6

    Monday

    Condensed-Matter Physics & Materials Science Seminar

    "Proximity effects in cuprate/manganite multilayers"

    Presented by Christian Bernhard, University of Fribourg, Germany

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

    Monday, November 6, 2017, 1:30 pm

    Hosted by: '''Chris Homes'''

    Recently we observed an intriguing, magnetic-filed-induced insulator-to-metal transition in YBa2Cu3O7/Pr1-xCaxMnO3 (YBCO/PCMO) multilayers [1]. In the low field regime, the response of these multilayers is highly resistive and resembles the one of granular superconductors or frustrated Josephson-networks. Notably, a coherent superconducting response can be restored with a large magnetic field. The latter also suppresses the charge/orbital order of the PCMO layers towards a ferromagnetic state. This coincidence suggests an intimate relationship between the insulator-to-superconductor transition in the YBCO layer and the suppression of the charge/orbital order in the PCMO. I will discuss the evidence, based on resonant x-ray scattering experiments, that the latter induces (or strongly enhances) a static Cu-CDW order in YBCO that is intertwined with superconductivity. [1] B.P.P. Mallett et al., Phys. Rev. B 94, 180503(R) (2016).

  13. NOV

    7

    Tuesday

    Physics Colloquium

    "Building an entanglement sharing quantum network"

    Presented by Professor Eden Figueroa, Stony Brook University

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

    Tuesday, November 7, 2017, 3:30 pm

    Hosted by: 'Andrei Nomerotski'

    In the first part of our talk we will show how to produce photonic quantum entanglement and how to store it and distribute it by optically manipulating the properties of room temperature atomic clouds. We will discuss our recent experiments in which several quantum devices are already interconnected forming an elementary quantum cryptographic network. We will also discuss our progress regarding the construction of an entanglement sharing link between Stony Brook and BNL. In the second part we will show our progress regarding the construction of an analog quantum computer capable of simulating relativistic dynamics using atoms and quantized light. We will show how our device is already capable of simulating Dirac and Jackiw-Rebbi Hamiltonians as well as the road map towards simulating Quantum Field Theory Hamiltonians.

  14. NOV

    8

    Wednesday

    HET Seminar

    "TBA"

    Presented by Linda Carpenter, Ohio State University

    2 pm, Small Seminar Room, Bldg. 510

    Wednesday, November 8, 2017, 2:00 pm

    Hosted by: 'Sally Dawson'

  15. NOV

    9

    Thursday

    Condensed-Matter Physics & Materials Science Seminar

    "Quasiparticle spectra from stochastic many-body methods"

    Presented by Vojtech Vlcek, University of California, Los Angeles

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

    Thursday, November 9, 2017, 1:30 pm

    Hosted by: ''Igor Zaliznyak''

    TBD

  16. NOV

    9

    Thursday

    Particle Physics - SB/BNL Joint Cosmo seminar (at BNL)

    "Dark Matter Searches with CCDs and the Sensei Experiment"

    Presented by Dr. Javier Tiffenberg, FNAL

    3 pm, Small Seminar Room, Bldg. 510

    Thursday, November 9, 2017, 3:00 pm

    Hosted by: ''Erin Sheldon''

  17. NOV

    14

    Tuesday

    Physics Colloquium

    "TBA"

    Presented by Christoph Lehner, BNL

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

    Tuesday, November 14, 2017, 3:30 pm

    Hosted by: ''Rob Pisarski''

  18. NOV

    15

    Wednesday

    HET Seminar

    "TBA"

    Presented by Thomas Appelquist, Yale University

    2 pm, Small Seminar Room, Bldg. 510

    Wednesday, November 15, 2017, 2:00 pm

    Hosted by: 'Sally Dawson'

  19. NOV

    16

    Thursday

    RIKEN Lunch Seminar

    "QCD from gluon, quark, and meson correlators"

    Presented by Mario Mitter, BNL

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

    Thursday, November 16, 2017, 12:30 pm

    Hosted by: 'Hiromichi Nishimura'

    We present non-perturbative first-principle results for quark-, gluon- and meson 1PI correlation functions of two-flavour Landau-gauge QCD in the vacuum and Yang-Mills theory at finite temperature. They are obtained by solving their Functional Renormalisation Group equations in a systematic vertex expansion, aiming at apparent convergence within a self-consistent approximation scheme. These correlation functions carry the full information about the theory and their connection to physical observables is discussed. The presented calculations represent a crucial prerequisite for quantitative first-principle studies of QCD and its phase diagram within this framework. In particular, we have computed the ghost, quark and scalar-pseudoscalar meson propagators, as well as gluon, ghost-gluon, quark-gluon, quark, quark-meson, and meson interactions and the magnetic and electric components of the gluon propagator, and the three- and four-gluon vertices. Our results stress the crucial importance of the quantitatively correct running of different vertices in the semi-perturbative regime for describing the phenomena and scales of confinement and spontaneous chiral symmetry breaking without phenomenological input. We confront our results for the correlators with lattice simulations and compare our Debye mass to hard thermal loop perturbation theory. Finally, applications to "QCD-enhanced" low-energy effective models of QCD are discussed.

  20. NOV

    16

    Thursday

    Condensed-Matter Physics & Materials Science Seminar

    "TBA"

    Presented by Zurab Guguchia, Columbia University

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

    Thursday, November 16, 2017, 1:30 pm

    Hosted by: ''Emil Bozin''

    TBA

  21. NOV

    21

    Tuesday

    Physics Colloquium

    "Numerical Relativity in the Multimessenger Era"

    Presented by Manuela Campanelli, Rochester Institute of Technology

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

    Tuesday, November 21, 2017, 3:30 pm

    Hosted by: 'Peter Petreczky'

    The recent discovery of gravitational waves by Advanced LIGO ushered in a new kind of astronomy, one potentially integrating its findings with those obtained from electromagnetic and/or neutrino observations. Multi-messenger astronomy promises to revolutionize our understanding of the universe by providing dramatically contrasting views of the same objects. To understand this unprecedented wealth of observational evidence, computer intensive theoretical calculations of the Einstein field equations, coupled with the equations of magneto-hydrodynamics, are required in order to link data with underlying physics. In this talk, I will provide a review on the recent progress in this exciting field of computational astrophysics. With Advanced LIGO now fully operational and the detection of additional gravitational wave events imminent, we expect that there will be a surge in the number of researchers interested in performing simulations of compact binary mergers.

  22. NOV

    29

    Wednesday

    HET/RIKEN Seminar

    "TBA"

    2 pm, Small Seminar Room, Bldg. 510

    Wednesday, November 29, 2017, 2:00 pm

    Hosted by: 'Sally Dawson'

  23. DEC

    6

    Wednesday

    HET/RIKEN Seminar

    2 pm, Small Seminar Room, Bldg. 510

    Wednesday, December 6, 2017, 2:00 pm

    Hosted by: 'Sally Dawson'

  24. DEC

    13

    Wednesday

    HET/RIKEN Seminar

    "TBA"

    2 pm, Small Seminar Room, Bldg. 510

    Wednesday, December 13, 2017, 2:00 pm

    Hosted by: 'Sally Dawson'

  25. FEB

    13

    Tuesday

    Physics Colloquium

    "The Multi-Messenger Picture of a Neutron Star Merger"

    Presented by Brian Metzger, Columbia University

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

    Tuesday, February 13, 2018, 3:30 pm

    Hosted by: 'Peter Petreczky'

    On August 17 the LIGO/Virgo gravitational wave observatories detected the first binary neutron star merger event (GW170817), a discovery followed by the most ambitious electromagnetic (EM) follow-up campaign ever conducted. A gamma-ray burst (GRB) of short duration and very low luminosity was discovered by the Fermi and INTEGRAL satellites within 2 seconds of the merger. Within 11 hours, a bright but rapidly-fading thermal optical counterpart was discovered in the galaxy NGC 4993 at a distance of only 40 Mpc. The properties of the optical transient match remarkably well predictions for kilonova emission powered by the radioactive decay of heavy nuclei synthesized in the expanding merger ejecta by the r-process. The rapid spectral evolution of the kilonova emission to near-infrared wavelengths demonstrates that a portion of the ejecta contains heavy lanthanide nuclei. Two weeks after the merger, rising non-thermal X-ray and radio emission were detected from the position of the optical transient, consistent with delayed synchrotron afterglow radiation from an initially off-axis relativistic jet with the properties consistent with those of (on-axis) cosmological short GRB. I will describe a unified scenario for the range of EM counterparts from GW170817 and their implications for the astrophysical origin of the r-process and the properties of neutron stars. I will preview the upcoming era of multi-messenger astronomy, once Advanced LIGO/Virgo reach design sensitivity and a neutron star merger is detected every few weeks.

  1. Condensed-Matter Physics & Materials Science Seminar

    "Pressure-driven collapse of Jeff=1/2 electronic state in a honeycomb iridate"

    Presented by Young-June Kim, University of Toronto, Canada

    Friday, October 20, 2017, 3 pm
    ISB Bldg. 734 Conf. Rm. 201 (upstairs)

    Hosted by: '''Igor Zaliznyak'''

    Orbital and spin degrees of freedom in heavy transition metal compounds can be locked into each other due to strong spin-orbit coupling. The magnetism in this case is described by an effective total angular momentum jeff=1/2 rather than usual spin angular momentum. Furthermore, these jeff=1/2 moments residing on a honeycomb lattice can be coupled through bond-dependent Kitaev interactions. Magnetic properties of some honeycomb lattice iridates, such as Na2IrO3 and Li2IrO3 have been extensively investigated to examine whether Kitaev quantum spin liquid is realized in these compounds. However, the applicability of the jeff=1/2 local moment model in real materials have not been critically scrutinized experimentally. A combination of x-ray absorption spectroscopy, x-ray diffraction, and resonant inelastic x-ray scattering experiments on a honeycomb lattice Li2IrO3 reveals that the jeff=1/2 picture breaks down under high pressure, and electrons take on more itinerant character under this condition.

  2. Nuclear Theory/RIKEN Seminar

    "Quantization of three-body scattering amplitude in isobar formulation"

    Presented by Maxim Mai, George Washington University

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

    Hosted by: ''Chun Shen''

    In the so-called isobar parametrization the three-particle states are populated via an interacting two-particle system (resonant or non-resonant), and a spectator. Using this parametrization, we derive the isobar-spectator interaction such that the three-body Unitarity is ensured exactly. In the first part of my talk I will show the major steps of this derivation. (arXiv:1706.06118) The second part of the talk will be dedicated to the finite-volume implementation of the framework (arXiv:1709.08222). Imaginary parts in the infinite volume, dictated by Unitarity, determine the dominant power-law finite volume effects to ensure the correct 3-body quantization condition. Furthermore, various building blocks of the 3->3 amplitude in the finite volume can become singular. However, when all contributions are summed-up, only genuine 3-body singularities remain. I will demonstrate the corresponding cancellation mechanisms explicitly for the simplified case of only one S-wave isobar.

  3. Particle Physics Seminar

    "Study of the Higgs properties in the H->ZZ*->4l channel with the ATLAS detector"

    Presented by Gaetano Barone, Brandeis University

    Thursday, October 19, 2017, 3 pm
    Small Seminar Room, Bldg. 510

    Hosted by: 'Alessandro Tricoli'

    Recent measurements of the Higgs boson properties in the four lepton channel for 36.1 fb-1 of proton—proton collisions at 13 TeV using the ATLAS detector will be presented. The measurements include the Higgs boson mass as well as inclusive, fiducial and differential cross sections and, constraints on Higgs boson production couplings. The results are interpreted within the Standard Model and various extensions.

  4. RIKEN Lunch Seminar

    "Lattice QCD and Neutrino Physics"

    Presented by Aaron Meyer, HET Group

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

    Hosted by: 'Enrico Rinaldi'

    The nucleon axial form factor is a dominant contribution to systematic uncertainties in neutrino oscillation studies. The most commonly used model parametrization of the axial form factor has uncontrolled and underestimated systematic errors. First-principles computations from lattice QCD have the potential to control theory errors by disentangling the effects of nuclear corrections from the nucleon amplitudes. In this talk, I discuss fits to the axial form factor with deuterium bubble chamber data using the model-independent $z$ expansion parameterization. I then present preliminary results for a blinded lattice QCD calculation of the nucleon axial charge $g_A$ with physical light quark masses. This calculation is being done with the Highly Improved Staggered Quark (HISQ) action and 2+1+1 flavors of sea quarks.

  5. Environmental & Climate Sciences Department Seminar

    "Desert Dust, Wildfire Smoke, Volcanic Ash, Urban and Industrial Pollution – Grasping the Role Particles Play in Global Climate and Regional Air Quality"

    Presented by Ralph Kahn, NASA Goddard Space Flight Center

    Thursday, October 19, 2017, 11 am
    Conference Room Bldg 815E

    Hosted by: 'Steve Schwartz'

    Airborne particles are ubiquitous components of our atmosphere, originating from a variety of natural and anthropogenic sources, exhibiting a wide range of physical properties, and contributing in multiple ways to regional air quality as well as regional-to-global-scale climate. Most remain in the atmosphere for a week or less, but can traverse oceans or continents in that time, carrying nutrients or disease vectors in some cases. Bright aerosols reflect sunlight, and can cool the surface; light-absorbing particles can heat the atmosphere, suppressing cloud formation or mediating larger-scale circulations. In most cases, particles are required to collect water vapor as the initial step in cloud formation, so their presence (or absence) and their hygroscopic or hydrophilic properties can affect cloud occurrence, structure, and ability to precipitate. Grasping the scope and nature of aerosol environmental impacts requires understanding microphysical-to-global scale processes, operating on timescales from minutes to days or longer. Satellites are the primary source of observations on kilometer-to-global scales. Spacecraft observations are complemented by suborbital platforms: aircraft in situ measurements and surface-based instrument networks that operate on smaller spatial scales, some on shorter timescales. Numerical models play a third key role in this work — providing a synthesis of current physical understanding with the aggregate of measurements, and allowing for some predictive capability. This presentation will focus on what we can say about aerosol amount and type from space. Constraining particle "type" is at present the leading challenge for satellite aerosol remote sensing. We will review recent advances and future prospects, including the strengths and limitations of available approaches, and current work toward better integrating measurements with models to create a clearer picture of aerosol environmental impacts, globally.

  6. HET Seminar

    "Semileptonic decays of B_(s) mesons to light pseudoscalar mesons with lattice QCD"

    Presented by Zechariah Gelzer, Iowa University

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

    Hosted by: '''Mattia Bruno'''

  7. Particle Physics Seminar

    "The R&D and Mass Production of 20"MCP-PMT for Neutrino Detection"

    Presented by Dr. Sen Qian, IHEP China

    Monday, October 16, 2017, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: 'Xin Qian'

    Researchers at IHEP, Beijing have conceived a new concept of MCP-PMT several years ago. The small MCP (Microchannel Plate) units replace the bulky Dynode chain in the tranditional large PMTs for better photoelectron detection. After three years R&D, a number of 8 inch prototypes were produced and their performance was carefully tested at IHEP in 2013 by using the MCP-PMT evaluation system built at IHEP. The 20 inch prototypes were followed in 2014, and its' performance were improving a lot in 2015. Compensating the PMT performances with fiducially volume convert all specifications to cost, radioactivity, dark noise, TTS, the JUNO ordered 15000 pic 20-inch MCP-PMT from the NNVT in Dec.2015. In 2016, the MCP-PMT collaboration group finished to build the mass production line in Nanjing at the end of 2016, and finished the batch test system in the same place within 100 days at the beginning of 2017. From 2017 to 2019, all the 20-inch MCP-PMT will be produced and tested one by one in NNVT for JUNO. This presentation will talk about the R&D process and mass production, batch test result of the first 2K pieces of MCP-PMT prototypes for JUNO.

  8. Condensed-Matter Physics & Materials Science Seminar

    "Domain walls and phase boundaries - new nanoscale functional elements in complex oxides"

    Presented by Jan Seidel, UNSW Sydney

    Monday, October 16, 2017, 1:30 pm
    Bldg. 480, Conference Room

    Hosted by: ''Myung-Geun Han''

    Topological structures in functional materials, such as domain walls and skyrmions, see increased attention due to their properties that can be completely different from that of the parent bulk material [1]. I will discuss recent results on multiferroic phase boundaries, domain walls in BiFeO3 [2, 3, 4, 5, 6] using SPM, TEM and ab-initio theory, and discuss future prospects [7]. References [1] J. Seidel (ed.), Topological structures in ferroic materials: domain walls, skyrmions and vortices, ISBN: 978-3-319-25299-5, Springer, Berlin (2016) [2] P. Sharma, et al., Scientific Reports 6, 32347 (2016) [3] P. Sharma, et al., Advanced Electronic Materials 2, 1600283 (2016) [3] J. Seidel, et al., Advanced Materials 26, 4376 (2014) [4] Y. Heo, et al., Advanced Materials 26, 7568 (2014) [5] Y. Heo et al., ACS Nano, DOI: 10.1021/acsnano.6b07869 (2017) [6] P. Sharma, et al., Advanced Materials Interfaces 3, 1600033 (2016) [7] J. Seidel, Nature Nanotechnology 10, 190 (2015)

  9. Nuclear Theory/RIKEN Seminar

    "What can we learn from flow observables in heavy-ion collisions?"

    Presented by Jacquelyn Noronha-Hostler, Rutgers University

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

    Hosted by: 'Chun Shen'

    The Quark Gluon Plasma (QGP), nature's first and most perfect liquid, has been successfully reproduced in heavy-ion collisions at RHIC and the LHC. The dynamics of the QGP can be well described by relativistic viscous hydrodynamics, allowing for precise comparisons to experimental data in order to extract the properties of the QGP. While a small shear viscosity is well-established, questions still remain regarding the precise initial state, the temperature dependence of viscosity, the smallest system that displays QGP-like properties, and the equation of state at large densities. In this talk, the various flow harmonic observables are analyzed to help answer these remaining questions.

  10. Particle Physics Seminar

    "SB/BNL Joint Cosmo Seminar (at Stony Brook)"

    Presented by Chang Feng, UC Irvine

    Wednesday, October 11, 2017, 1:30 pm
    Stony Brook

    Hosted by: '''Neelima Sehgal'''

  11. HET Lunch Discussions

    "Repulsion of Dark Matter and Null Direct Signals"

    Presented by Hooman Davoudiasl, BNL

    Friday, October 6, 2017, 12:15 pm
    Building 510, Room 2-160

    Hosted by: 'Christoph Lehner'

  12. HET Seminar

    "Flavorful Higgs bosons"

    Presented by Wolfgang Altmannshofer, Cincinnati University

    Wednesday, October 4, 2017, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: ''Sally Dawson''

    Measurements of Higgs production and decays have revealed that most of the mass of the weak gauge bosons is due to the 125 GeV Higgs. Similarly, we know that the Higgs is at least partially responsible for giving mass to the top and bottom quarks and the tau lepton. Much less is known about the origin of mass for the first two generations. In this talk, I will discuss a framework in which the first and second generation masses originate from a second source of electroweak symmetry breaking and outline the phenomenological implications.

  13. Nuclear Physics Seminar

    "The nature of flow fluctuations, from pp to A+A, and back again"

    Presented by Mingliang Zhou, Stony Brook University

    Tuesday, October 3, 2017, 11 am
    Small Seminar Room, Bldg. 510

    Hosted by: 'Jiangyong Jia'

    In recent years, there have been rapid progresses in our understanding of the event-by-event flow fluctuation, which provides direct insight into the fluctuations in the initial geometry. I will start my talk by briefly discussing the flow (collectivity) and its fluctuation in small systems pp and p+Pb, using the newly-proposed subevent cumulant method, which is able to suppress the non-flow background effectively. I will show there is significant fluctuation of elliptic flow $v_2$ in pp and non-Gaussian fluctuation of triangular flow $v_3$ in p+Pb. Moving from small to large systems, STAR collaboration recently has shown different behaviors of cumulant $c_2\{4\}$ between Au+Au and U+U in ultra-central collisions, which is believed to support the different geometry fluctuations. By presenting the newest ATLAS flow measurements in ultra-central collisions, together with detailed MC Glauber studies, I will explain why sign change of $c_2\{4\}$ is observed and its implications. In the end, I will go back to small systems and discuss the potential impact of centrality resolution on pp flow measurements.

  14. Particle Physics Seminar

    "Latest Results from the T2K Experiment"

    Presented by Kendall Mahn, Michigan State University

    Friday, September 29, 2017, 3:30 pm
    Small Seminar Room, Bldg. 510

    Hosted by: ''Xin Qian''

    One of the most promising investigations of beyond-the-Standard-Model physics has been the study of neutrino oscillation, that is, the conversion of neutrinos from one flavor to another as they propagate. While neutrino oscillation is studied in a wide variety of experiments, accelerator based experiments, such as T2K, use a muon neutrino or antineutrino beam as a source to look for electron (anti)neutrino appearance, muon neutrino disappearance. The source also is used to make measurements of neutrino interactions and search for exotic physics. This talk will describe a recent analysis of both neutrino and antineutrino beam data from T2K. Comparisons between neutrino and antineutrino event rates provide a tantalizing window on possible CP violation in the neutrino sector. The talk will also highlight the increasingly important role of systematic uncertainty assessment for T2K and other future measurements of CP violation with accelerator beams.

  15. Nuclear Theory/RIKEN Seminar

    "QCD on a small circle"

    Presented by Aleksey Cherman, University of Washington

    Friday, September 29, 2017, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: ''Heikki Mantysaari''

    Recent developments have shown that QCD-like theories can be engineered to remain in a confined phase when compactified on an arbitrarily small circle, where their features may be studied quantitatively in a controlled fashion. I'll explain how a non-perturbative mass gap and chiral symmetry breaking, which are both historically viewed as prototypical strong coupling effects, appear from systematic weak-coupling calculations. Then I'll describe the rich spectrum of hadronic states, including glueball, meson, and baryon resonances in the calculable small-circle context.

  16. Particle Physics Seminar

    "Beauty and charm decays and physics beyond the Standard Model: an experimentalist perspective"

    Presented by Marina Artuso, Syracuse University

    Thursday, September 28, 2017, 3 pm
    Small Seminar Room, Bldg. 510

    Hosted by: 'Alessandro Tricoli'

    The Standard Model provides a comprehensive explanation for a vast array of data collected at different experiments. Nonetheless fundamental questions remain unanswered and the search for a more complete theory is still a coveted goal of particle physics. Recently, tensions with standard model predictions have been uncovered in several experimental observables in b-hadron decays at LHCb. I will discuss the data, possible implications, and the connection with other experimental programs such as study of kaon rare decays and neutrino mixing and CP violation

  17. Condensed-Matter Physics & Materials Science Seminar

    "Suppression of weak ferromagnetism in ultrathin iridates by interfacial engineering of octahedral rotations"

    Presented by Yuefeng Nie, Nanjing University, China

    Thursday, September 28, 2017, 1:30 pm
    ISB Bldg. 734 Conf. Rm. 201 (upstairs)

    Hosted by: '''Weiguo Yin'''

    Layered iridates, Srn+1IrnO3n+1, have drawn great attention since they share remarkable similarities with high-Tc cuprates, including layered crystalline structure, (pseudo) spin ½ states, antiferromagnetic (AFM) Mott insulating ground state, Fermi arcs, and V shape energy gap, etc. Nonetheless, direct evidences of superconductivity such as zero resistivity and Meissner effect are still lacking up to date. The strong spin-orbit coupling and IrO6 octahedral rotations in 5d iridates result in a canted AFM ground state with weak ferromagnetic moments in each IrO2 plane. Here, we propose to suppress the weak ferromagnetism by suppressing the octahedral rotations in iridates, which may facilitate the Cooper pairing. Using a combination of reactive molecular beam epitaxy (MBE), in situ angleresolved photoemission spectroscopy (ARPES) and first principle calculations, we investigate the evolution of octahedral rotations, electronic structure and magnetic ordering in ultra-thin SrIrO3 films grown on (001) SrTiO3 substrate. Our experimental results and theoretical calculations show that octahedral rotations and weak ferromagnetic moments are fully suppressed in 1 and 2 unit cell thick SrIrO3 films through interfacial clamping effects. If time allows, I will also present our recent work on the new understanding of RHEED oscillations in the growth of oxides and the chemically specific termination control of oxide interfaces via layerby- layer mean inner potential engineering.

  18. RIKEN Lunch Seminar

    "Color Memory, Large Gauge Transformations, and Soft Theorems in Yang-Mills Theory"

    Presented by Monica Pate, Harvard University

    Thursday, September 28, 2017, 12:30 pm
    Building 510, Room 2-160

    Hosted by: '''Hiromichi Nishimura'''

    An infinite dimensional symmetry group which governs the infrared sectors of gauge and gravity theories has been recently discovered. This symmetry can be established both from an asymptotic symmetry analysis as well as from the corresponding Ward identities which are quantum field theoretic soft theorems. Moreover, the spontaneous breaking of these symmetries induces vacuum transitions which are detectable by charged particles through the so-called memory effect. In this seminar, I will explain the precise equivalence between asymptotic symmetries, soft theorems and memory effects in the context of tree level Yang-Mills. In particular, in this context the soft gluon theorem is Ward identity of a large gauge symmetry, whose action on the vacuum can be measured from the relative color charge of colored detectors.

  19. Condensed-Matter Physics & Materials Science Seminar

    "Ultrafast TEM and Time-of-Flight EELS using microwave cavities"

    Presented by Jom Luiten, Eindhoven University of Technology, Netherlands

    Friday, September 22, 2017, 11 am
    Bldg. 480, Conference Room

    Hosted by: '''Yimei Zhu'''

    Ultrafast Transmission Electron Microscopy (U-TEM) has become a very important tool for the study of ultrafast phenomena at (sub-)nm length scales and (sub-)ps time scales. U-TEM is usually based on the creation of ultrashort electron pulses by femtosecond laser photoemission from a flat cathode, with the result that both the beam quality and the average current are significantly less than in state-of-the-art continuous-beam TEMs. At Eindhoven University we have developed U-TEM in which ultrashort electron pulses are produced by using a 3 GHz deflecting microwave cavity in TM110 mode to sweep a high-brightnes continuous beam across a slit [1]. We have demonstrated ultrafast beam chopping with conservation of the beam quality and the sub-eV energy spread of the FEG source of an adapted 200 keV Tecnai TEM, enabling atomic resolution with sub-ps temporal resolution at 3 GHz rep rate [2] In addition we have developed a new method for doing Time-of-Flight Electron Energy Loss Spectroscopy (ToF-EELS) based on the combined use of two TM110 deflecting cavities and two TM010 (de)compression cavities. The first 'chopping' TM110 cavity produces ultrashort electron pulses which are sent through a sample. Energy loss in the sample translates into reduction of the electron velocity and thus into a later arrival time at the detector, which is measured with a synchronized second TM110 'streak' cavity. In this way an energy resolution of 12 eV at 30 keV has been demonstrated [3]. By adding a TM010 (de)compression cavity after the sample, the longitudinal phase space can be manipulated in such a way that the energy resolution is improved to 2 eV (to be published). By adding a second TM110 cavity before the sample, full control over the longitudinal phase space can be achieved. Detailed charged particle tracking simulations show that an energy resolution of 20 meV combined with a temporal resolution of 2 ps can be achieved; or, alternatively, 2

  20. Particle Physics Seminar

    "Evidence for the H to bb decay with the ATLAS detector"

    Presented by Giacinto Piacquadio, Stony Brook University

    Thursday, September 21, 2017, 4 pm
    Small Seminar Room, Bldg. 510

    Hosted by: 'Alessandro Tricoli'

    Most Higgs bosons are expected to decay to a pair of b-quarks, with the Standard Model predicting a branching fraction of about 58%. Probing this decay is important to furthering our understanding of the Higgs sector, but its observation at hadron colliders is complicated by overwhelming Standard Model backgrounds. In this seminar, the search for the Higgs to bb decay, looking at the associated production of the Higgs boson with a W or Z boson, is presented, based on 36 fb-1 of 13 TeV LHC Run 2 data.

  21. Condensed-Matter Physics & Materials Science Seminar

    "Two new applications of geometric critical phenomena for disordered electron systems"

    Presented by Matthew Foster, Rice University

    Thursday, September 21, 2017, 1:30 pm
    ISB Bldg. 734 Conf. Rm. 201 (upstairs)

    Hosted by: ''Robert Konik''

    I will discuss two very recent results relating to the properties of electrons in two spatial dimensions (2D), subject to the effects of quenched disorder (impurities) and quantum interference [Anderson (de)localization]. In both cases, the key physics is tied to classical geometric critical phenomena in 2D. I will first present numerical evidence that strongly suggests the equivalence of disordered surface states of topological superconductors and geometric percolation. Percolation is known to play a role in quantum Hall systems with magnetic fields. Our unexpected result implies that percolation applies to topological superconductor surface states in the absence of time-reversal symmetry breaking. Moreover, the usual "even-odd" effect that occurs in such a system (as identified by Pruisken in the integer quantum Hall effect and by Haldane for spin chains) is found to be absent. Second, I will discuss a "toy model" for the ergodic to many-body localized phase transition in 2D, and relate it to an effective self-interacting walk. I will present analytical results of a controlled expansion which suggest that the transition can be viewed as a "dephasing catastrophe."

  22. Nuclear Theory/RIKEN Seminar

    "TMD gluon distributions for dijet production and their behavior at small x"

    Presented by Elena Petreska, NIKHEF

    Friday, September 15, 2017, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: ''Heikki Mantysaari''

    Starting from the Color Glass Condensate (CGC) cross section for dijet production in proton-nucleus collisions we derive a transverse-momentum-dependent (TMD) factorization formula for small transverse-momentum imbalance of the jets and for finite number of colors. For the eight TMD distributions appearing in the cross section we determine their operator definitions at small-x as CGC correlators of Wilson lines and we study their JIMWLK evolution. We find that at large transverse momentum the universality of TMDs gets restored. We also discuss an extension of the approach to generalized TMDs (GTMDs) that can give an insight into the angular correlations between impact parameter and dipole size in the CGC framework.

  23. HET Lunch Discussions

    "Precision calculation of the g-2 HVP contribution by combining lattice and R-ratio data"

    Presented by Christoph Lehner, BNL

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

  24. Particle Physics Seminar

    "SB/BNL Joint Cosmo seminar (at BNL): Mapping the Cosmos with the Dark Energy Survey"

    Presented by Dr. Chihway Chang, ETH Zurich

    Thursday, September 14, 2017, 3 pm
    Small Seminar Room, Bldg. 510

    Hosted by: '''Erin Sheldon'''

    The first year data from the Dark Energy Survey (DES Y1) provides the most powerful optical survey dataset to date. In this talk I will first give an overall summary of the cosmology results from the DES Y1 dataset combining galaxy clustering and weak gravitational lensing. Next, I will describe our work in generating and testing the wide-field weak lensing mass maps from the galaxy shape measurements and some exciting applications for the maps. I will end with thoughts on how weak lensing could also inform us on various topics of galaxy formation, which is essential for completing the story behind the Universe we see today.

  25. RIKEN Lunch Seminar

    "Thermal Fluctuations in Hydrodynamic Simulations of QGP"

    Presented by Mayank Singh, McGill University

    Thursday, September 14, 2017, 12:30 pm
    Building 510, Room 2-160

    Hosted by: ''Hiromichi Nishimura''

    Multi-particle correlations measured in heavy-ion collision experiments carry info on fluctuations present in the entire evolutionary history of the system. Initial states include geometric and quantum fluctuations and are important contributors. The thermal fluctuations during the course of QGP evolution is another conceptually important source of these fluctuations and should be studied in detail. We begin by treating thermal fluctuations as a linearized perturbation on hydrodynamic background. We present a full calculation of hadronic and photonic observables including these fluctuations. Recently we have included fluctuations in our simulations in a non-perturbative manner. Progress based on this approach will be discussed.

  26. Physics Colloquium and Leona Woods Lecture

    "Momentum-space structure of hadrons and nuclei at high energy"

    Presented by Elena Petreska, NIKHEF

    Tuesday, September 12, 2017, 3:30 pm
    Large Seminar Room, Bldg. 510

    Hosted by: 'Peter Petreczky'

    Transverse-momentum-dependent (TMD) distributions describe the configuration of quarks and gluons inside protons and nuclei in three-dimensional momentum space. Observables in scattering experiments can be calculated with the help of TMD factorization formulas, where the target and projectile are represented with non-perturbative TMD distributions, which are separated from the short-distance perturbative part of the collision. A complementary approach to study the momentum structure of protons and nuclei at high energy is the Color Glass Condensate which is an effective theory for the high-gluon-density region of ultra-relativistic particles. We introduce both theories and we discuss connections between them. We present phenomenological results derived from these connections.

  27. NSLS-II Seminar

    "On the assessment of radiation damage and high temperature effects in novel nuclear materials using the BNL accelerators and synchrotrons"

    Presented by Nick Simos, Sr Scientist Emeritus, BNL

    Friday, September 8, 2017, 3 pm
    Large Seminar Room, Bldg. 510

    Hosted by: ''Ron Pindak''

    In search for new and improved materials, composites and super-alloys capable of withstanding the anticipated extreme states associated fusion reactors; high temperature fast reactors and multi-MW particle accelerators, novel reactor steels, super-alloys and composites are continuously being explored to help meet both the challenge of the higher demand environments and the intended application. Higher fluxes and fluences of irradiating species (neutrons and/or protons), extreme temperatures and aggressively corrosive environments make up the new cocktail of operating conditions of the new array of material structures. One of the challenges in characterizing the effects that high radiation fluxes of neutrons and protons induce on these novel material structures in conjunction with high temperatures is the link between lattice induced damage and phase transformation and macroscopic physical properties which ultimately determine performance in the real environment. High energy X-rays at the BNL synchrotrons have offered a path in establishing this important connection between micro-scale effects and physical properties of novel material structures exposed to high radiation fluxes. Specifically, by integrating the unique capabilities of the BNL accelerator complex that includes, in addition to the NSLS and NSLS II, the proton accelerator and Tandem as well as those of CFN, the evolution and/or damage of materials ranging from classical structures such as graphite, beryllium and steels to novel super-alloys, such as those of Invar and "Gum" metal, and new composites have been characterized both at the two length scales. The pivotal role of high energy X-rays from NSLS to NSLS II in making the connection will be presented demonstrating the enormous potential of the NSLS II in answering fundamental questions in our path towards the next generation nuclear materials. Furthermore, first glimpses of the correlation of lattice effects or damage induced by differ

  28. HET Lunch Discussions

    "Towards a non-perturbative calculation of Weak Hamiltonian Wilson Coefficients"

    Presented by Mattia Bruno, BNL

    Friday, September 8, 2017, 12:15 pm
    Building 510, Room 2-160

    Hosted by: 'Christoph Lehner'

  29. NSLS-II Colloquium Series

    "Experiments, Analyses, and Manipulations with Particle Beam"

    Presented by Shyh-Huan Lee, Indiana University, IN

    Thursday, September 7, 2017, 4 pm
    Large Seminar Room, Bldg. 510

    Hosted by: ''''''''''John Hill''''''''

    Progress on particle beam physics research have provided marked improvements in beam intensity, brightness, and stability advancing frontier research in applied and fundamental science. This talk will review some beam measurements and manipulation studies being undertaken to improve beam performance in storage rings. Hopefully, these studies will be relevant to the operation and improvement of National Accelerator User Facilities.

  30. Particle Physics Seminar

    "Radiation damage study of a thin YAG:Ce scintillator using low-energy protons"

    Presented by Dr. Vladmir Linhart, Czech Technical University in Prague

    Thursday, September 7, 2017, 3 pm
    Small Seminar Room, Bldg. 510

    Hosted by: '''Xin Qian'''

    Radiation hardness of a 50µm thin YAG:Ce scintillator in a form of dependence of a signal efficiency on 3.1MeV proton ?uence was measured and analyzed using X-ray beam. The signal efficiency is a ratio of signals given by a CCD chip after and before radiation damage. The CCD chip was placed outside the primary beam because of its protection from damage which could be caused by radiation. Using simplified assumptions, the 3.1MeV proton fluencies were recalculated to: • 150 MeV proton fluencies with intention to estimate radiation damage of this sample under conditions at proton therapy centers during medical treatment, • 150 MeV proton doses with intention to give a chance to compare radiation hardness of the studied sample with radiation hardness of other detectors used in medical physics, • 1 MeV neutron equivalent fluencies with intention to compare radiation hardness of the studied sample with properties of position sensitive silicon and diamond detectors used in nuclear and particle physics. The following results of our research were obtained. The signal efficiency of the studied sample varies slightly (±3%) up to 3.1MeV proton ?uence of c. (4 − 8) × 1014 cm−2. This limit is equivalent to 150MeV proton ?uence of (5 − 9) × 1016 cm−2, 150MeV proton dose of (350 − 600) kGy and 1MeV neutron ?uence of (1 − 2) × 1016 cm−2. Beyond the limit, the signal efficiency goes gradually down. Fifty percent decrease in the signal efficiency is reached around 3.1MeV ?uence of (1 − 2) × 1016 cm−2 which is equivalent to 150 MeV proton ?uence of around 2 × 1018 cm−2, 150MeV proton dose of around 15 MGy and 1 MeV neutron equivalent ?uence of (4 − 8) × 1017 cm−2. In contrast with position sensitive silicon and diamond radiation detectors, the studied sample has at least two order of magnitude greater radiation resistance. Therefore, YAG:Ce sci

  31. Simons Center for Geometry and Physics Public Lecture

    "Mysteries of the Universe and Everyday Life"

    Presented by Michelangelo Mangano; Young-Kee Kim; Joe Lykken, LHC/CERN; University of Chicago; Fermilab

    Tuesday, September 5, 2017, 5:30 pm
    Simons Center at Stony Brook University, Della Pie

    In the past few decades we have learned a great deal about the basic laws of Physics in the infinitely small – and the infinitely large – and how the two are intimately connected. New windows have expanded our understanding, and many unexpected questions have emerged. This is an exhilarating time in history. New tools, both theoretical and observational, may lead in the next decade to major advances in our understanding of the universe. As in the past, when major discoveries are made about the fundamental laws of Nature, not only is our view of the world enriched, but also our life is transformed. A good place to explore the discoveries from the past decades is in the description of symmetry, symmetry breaking and the Higgs boson in High Energy Physics: why, how and where to…. in a nutshell. These talks will present what we know and what we seek in the fundamental laws of Nature; how we go about answering basic questions in high energy experiments, how much we have learned, and how the technical developments needed to make discoveries have changed society. They will also delineate the boundaries of our knowledge and the known unknowns in fundamental high energy physics and cosmology.

  32. HET Lunch Discussions

    "Finite Volume in QCD+QED & g-2 HLbL"

    Presented by Taku Izubuchi, BNL

    Friday, September 1, 2017, 12:15 pm
    Building 510, Room 2-160

    Hosted by: ''Christoph Lehner''

  33. Particle Physics Seminar

    "Wiener-SVD approach to data unfolding"

    Presented by Dr. Hanyu Wei, BNL

    Thursday, August 31, 2017, 3 pm
    Small Seminar Room, Bldg. 510

    Hosted by: 'Xin Qian'

    Data unfolding is a commonly used technique in the high energy physics experiments, to retrieve the distorted or transformed measurements by various detector effects. Inspired by the deconvolution technique in the digital signal processing, a new unfolding technique based on the Singular Value Decomposition (SVD) of the response matrix is developed. With the well-known Wiener filter concept, the modified SVD approach, Wiener-SVD, achieves the maximizing signal-to-noise ratio of the binned data in a transformed set of orthonormal bases where the uncertainties are bin-to-bin uncorrelated. In this talk, the mathematical principles and formulations of the newly developed Wiener-SVD unfolding will be presented. A few applications will be demonstrated. A comparison with the commonly used regularization method will also be shown. The advantages and disadvantaged of the Wiener-SVD approach will be discussed.

  34. Nuclear Theory/RIKEN Seminar

    "QCD corrections to high-pT hadron production in ep scattering"

    Presented by Werner Vogelsang, Tuebingen University

    Friday, August 25, 2017, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: 'Heikki Mantysaari'

    We discuss various cross sections and spin observables in high-pT hadron production in lepton proton collisions, with special focus on the role of perturbative QCD corrections. We present phenomenological studies relevant for present fixed-target experiments and for a future EIC.

  35. Particle Physics Seminar

    "Precision tests with antimatter: A glimpse at the 1S – 2S transition in trapped antihydrogen"

    Presented by Dr. William Bertsche, CERN

    Thursday, August 24, 2017, 10 am
    Small Seminar Room, Bldg. 510

    Hosted by: 'Xin Qian'

    Optical spectroscopy with antihydrogen atoms remains one of the most promising routes towards testing CPT invariance and physics beyond the Standard Model in an effort to address the observed Baryon asymmetry in the Universe today. The ALPHA collaboration has made significant progress towards the first measurements of optical transitions in trapped antihydrogen atoms, and has recently published the first observation of the 1S – 2S transition in a fully antimatter atom. This work finds the transition consistent with CPT invariance at a level of approximately 2 x 10-10 [1]. This talk will review the details of this pioneering experiment and discuss the prospects of future spectroscopy studies and other fundamental measurements with the ALPHA experiment. [1] M. Ahmadi, et al (ALPHA Collaboration), "Observation of the 1S–2S transition in trapped antihydrogen" Nature 541, 506–510 (2017).

  36. Condensed-Matter Physics & Materials Science Seminar

    "Experiments on electron hydrodynamics with and without applied magnetic fields"

    Presented by Andrew Mackenzie, Max-Planck-Institute, Germany

    Wednesday, August 23, 2017, 1:30 pm
    Bldg. 734, ISB Conf. Room 201 (upstairs)

    Hosted by: '''Cedomir Petrovic'''

    Will discuss experiments aimed at probing signatures of viscous contributions to electrical transport in ultra pure metallic systems. The hydrodynamic regime was reached in semiconductor heterostructures in the 1990s, but has only recently come into reach in naturally occurring compounds. I will focus on our group's work on layered delafossite metals, but possibly also discuss results from other groups on different material families.

  37. Nuclear Theory/RIKEN Seminar

    "Factorization and phenomenology for Transverse Momentum Dependent distributions"

    Presented by Ignazio Scimemi, Universidad Complutense de Madrid

    Friday, August 18, 2017, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: 'Heikki Mantysaari'

    Factorization and phenomenology for Transverse Momentum Dependent distributions Abstract: The factorization of the hadronic part of the cross sections plays a central role in our comprehension of collider physics. I will review some aspects of the factorization, like the appearence of rapidity divergences and the related subtractions and log resummation (up to higher orders in QCD perturbative expansion) in transverse momentum dependent cross sections. As an application I will describe the inclusion of the TMD formalism in an analysis of vector boson production data.

  38. RIKEN Lunch Seminar

    "Revisit the energy density and the gluon spectrum in the boost-invariant Glasma from a semi-analytic approach"

    Presented by Ming Li

    Thursday, August 17, 2017, 12:30 pm
    Building 510, Room 2-160

    Hosted by: '''Hiromichi Nishimura'''

    In high energy heavy-ion collisions, the soft degrees of freedom at the very initial stage after the collision can be effectively represented by strong classical gluonic fields within the Color Glass Condensate framework. Understanding the space-time evolution of the system is equivalent to solving the classical Yang-Mills equations for the gluonic fields. There have been many efforts in the past two decades in numerically solving these equations. In this talk, on the contrary, I will use a semi-analytic approach that assumes the solution has the form of a power series expansion in the proper time. I will discuss the energy-momentum tensor and the gluon spectrum obtained from this approach and make comparisons with the numerical results in the literature.

  39. Special Nuclear Theory Seminar

    "Gluon orbital angular momentum at small-x"

    Presented by Yoshitaka Hatta, YITP, Kyoto University

    Wednesday, August 16, 2017, 10:30 am
    Small Seminar Room, Bldg. 510

    Hosted by: 'Raju Venugopalan'

    After reviewing the general aspects of the partonic orbital angular momentum in QCD (rigorous definition, connection to the Wigner distribution, etc), I focus on the gluon OAM in the small-x regime and discuss its measurability and a possible relation to the polarized gluon distribution.

  40. Nuclear Theory/RIKEN Seminar

    "Resummation of nonglobal logarithms in QCD"

    Presented by Yoshitaka Hatta, Kyoto University

    Friday, August 11, 2017, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: 'Heikki Mantysaari'

    The large angle emission of soft gluons from QCD jets gives rise to the so-called nonglobal logarithms. In this talk I discuss the resummation of nonglobal logarithms at finite Nc with particular emphasis on its deep connection to the small-x logarithms in high energy scattering.

  41. HET Lunch Discussions

    "Hierarchion - a unified framework to address the Standard Model's hierarchies"

    Presented by Gilad Perez, Weizmann Institute

    Friday, August 11, 2017, 12:15 pm
    Building 510, Room 2-160

    Hosted by: ''Christoph Lehner''

  42. Brookhaven Lecture

    "516th Brookhaven Lecture: 'From NSLS to NSLS-II and Beyond: Accelerator Physics Challenges'"

    Tuesday, August 8, 2017, 4 pm
    Berkner Hall Auditorium

    Hosted by: ''Larry Carr''

  43. Nuclear Theory/RIKEN Seminar

    "General formulae for dipole Wilson line correlators with the Color Glass Condensate"

    Presented by Kenji Fukushima, University of Tokyo

    Friday, August 4, 2017, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: ''Heikki Mantysaari''

    I talk about general formulae to compute Wilson line correlators with the Color Glass Condensate approximated by the McLerran-Venugopalan model. Specifically, as an application, I explain about a perturbative expansion of the dipole correlators in terms of 1/N_c to derive fully analytical expressions. I finally discuss the validity of the large-N_c expansion by calculating the higher-order harmonics of the flow observables in the dipole model.

  44. HET Lunch Discussions

    "The Standard Model as a Lamppost"

    Presented by Eder Izaguirre, BNL

    Friday, August 4, 2017, 12:15 pm
    Building 510, Room 2-160

    Hosted by: ''''Christoph Lehner''''

  45. NSLS-II Friday Lunchtime Seminar Series

    "From Particles to Patients: The Role of an Epoxide Hydrolase in P. Aeruginosa Virulence"

    Presented by Kelli Hvorency, 2017 Julian D. Baumert. PhD. Thesis Award Winner, Dartmouth College

    Friday, August 4, 2017, 12 pm
    NSLS-II Bldg 743 (LOB 3), room 156

    Hosted by: ''Ben Ocko, Shirish Chodankar, Milinda Abeykoon, Juergen Thieme and Guimei Wang''

  46. HET Lunch Discussions

    "Possible origin(s) of flavor anomalies"

    Presented by Amarjit Soni, BNL

    Friday, July 28, 2017, 12:15 pm
    Building 510, Room 2-160

    Hosted by: ''Christoph Lehner''

  47. Particle Physics Seminar

    "Latest Results from NOvA"

    Presented by Louise Suter, Fermilab

    Thursday, July 27, 2017, 3 pm
    Small Seminar Room, Bldg. 510

    Hosted by: ''Xin Qian''

    NOvA is a long-baseline neutrino experiment which utilizes two basically fully active, finely segmented, liquid scintillator detectors: a Near Detector located at Fermilab, and a Far Detector located in Ash River, MI, and situated roughly 14 mrad off Fermilab's NuMI beam. Using this narrow-band beam of mostly muon neutrinos we study the oscillation of these neutrinos over the 810 km baseline to measure the rate of electron neutrino appearing and of muon neutrinos and neutral current interactions disappearing between the two detectors. These are interpreted to give our latest measurements on the neutrino mass ordering, CP violation, the flavor content of the third neutrino mass eigenstate, and tests of the three-neutrino paradigm.

  48. Computational Science Initiative Event

    "The AMReX Astrophysics Suite: Simulating the Stars at the Exascale"

    Presented by Michael Zingale, Associate Professor, Dept. Of Physics and Astronomy, Stony Brook University

    Thursday, July 27, 2017, 1:30 pm
    Seminar Room, Bldg. 725

    Hosted by: 'Meifeng Lin'

    Astronomy is an observational science — we take data (primarily light) from the objects in the Universe and use this to infer how systems work. Astrophysical simulations allow us to perform virtual experiments on these systems, giving us the ability to see into stars in a way that light alone does not allow. Stellar systems can be modeled using the equations of hydrodynamics, together with nuclear reactions, self-gravity, complex equations of state, and at times, radiation (and magnetic fields). The resulting simulation codes are multiphysics and multiscale, and a variety of techniques have been developed to permit accurate and efficient simulations. We describe the adaptive mesh refinement (AMR) codes for astrophysics built upon the AMReX library: the AMReX Astrophysics Suite. We'll focus on the codes for stellar / nuclear astrophysics: Maestro and Castro. Maestro models subsonic stellar flows while Castro focuses on highly-compressible flows. They share the same microphysics (reaction networks, equations of state) and parallelization strategy. Through AMReX, we distribute boxes in our AMR hierarchy across nodes and we use OpenMP (via a logical tiling model in Castro) to spread the work on a box across cores in a node. Recently we've implemented a GPU strategy in AMReX that allows us to move the computational kernels onto GPUs to offload expensive calculations. We'll discuss the current performance of the hydrodynamics and reaction networks on GPUs and how our strategy will evolve in the future.

  49. Environmental & Climate Sciences Department Seminar

    "Classifying Aerosol Particles with a Centrifugal Particle Mass Analyzer (CPMA)"

    Presented by Kristen Okorn, Stevens Institute of Technology (SULI Student Summer 2017)

    Thursday, July 27, 2017, 11 am
    Conference Room Bldg 815E

    Hosted by: 'Ernie Lewis'

    Although wood stoves are a carbon-neutral renewable energy source, they are the largest source of particulate matter (PM) emissions in New York State. A Differential Mobility Analyzer (DMA), which classifies particles by their mobility diameter, has traditionally been employed to characterize such particulate emissions. However, because the black carbon (BC) particles produced by combustion that contribute to PM are fractal, their mobility diameters are not equal to their mass-equivalent diameters. In contrast to the DMA, the Centrifugal Particle Mass Analyzer (CPMA) classifies aerosol particles by their mass, using two rotating cylinders and an electric potential; when the centrifugal and electrostatic forces on a particle are equal, it passes through. The CPMA can select particles with masses ranging from 2×10 4 to 1.05×103 fg (corresponding to diameters, for particles with density 1 g cm 3, ranging from 7 to 1300 nm). It can be operated in two different ways: the "Run" classification method can be used to select for a single particle mass, and the "Step Scan" method can be used to select particles over a set range of masses. A neutralizer must be used upstream of the CPMA to create a charge distribution on particles before they enter the instrument. A DMA can optionally be used to pre-select particles of a specific mobility diameter before entering the CPMA. Downstream of the instrument, a Condensation Particle Counter (CPC) must be used in order to determine the number concentration of particles that pass through the CPMA. The basic operating principles of the CPMA are discussed, and results are presented for its characterization of polystyrene latex (PSL) particles, ammonium sulfate particles, and emissions from a wood burning stove.

  50. HET Lunch Discussions

    "Quasi PDFs"

    Presented by Luchang Jin, BNL

    Friday, July 21, 2017, 12:15 pm
    Building 510, Room 2-160

    Hosted by: 'Christoph Lehner'

  51. Particle Physics Seminar

    "W boson mass measurement with the ATLAS experiment"

    Presented by Fabrice Balli, CEA Saclay

    Thursday, July 20, 2017, 3 pm
    Small Seminar Room, Bldg. 510

    Hosted by: 'Alessandro Tricoli'

    The W boson mass is a fundamental parameter of the Standard Model (SM) and was measured by several experiments at high energy e+e- and ppbar colliders. This parameter's measurement has the biggest impact on indirect searches for new particles or interactions, by comparing the measurement of this parameter with the prediction from the SM. It was measured recently by the ATLAS experiment at LHC, using data recorded in 2011, with a centre of mass energy of 7 TeV. I will review the thorough work that was performed in the ATLAS collaboration for this measurement and will discuss some considerations for future measurements at the LHC.

  52. HET Lunch Discussions

    "Long-lived light scalars and displaced vertices as probe of seesaw"

    Presented by Bhupal Dev, Washington University

    Friday, July 14, 2017, 12 pm
    Building 510, Room 2-160

    Hosted by: 'Amarjit Soni'

    In low-scale seesaw models for neutrino masses with local B −L symmetry breaking, the Higgs field breaking the B −L symmetry can leave a physical real scalar field with mass around GeV scale. In the specific case when the B − L symmetry is embedded into the left-right symmetry, low energy flavor constraints necessarily require such a light scalar to be long lived, with a distinct displaced photon signal at the LHC. We will discuss this previously unexplored region of parameter space, which opens a new window to TeV scale seesaw physics at colliders.

  53. NSLS-II Friday Lunchtime Seminar Series

    "Bio-cryo Electron Microscopy: The Opportunity and Plan" and "Characterizing Self-Assembled Nanoparticles Employed in Drug Delivery Systems"

    Presented by Sean McSweeney and Kazuo Sakurai, NSLS-II, BNL and University of Kitakyushu

    Friday, July 14, 2017, 12 pm
    NSLS-II Bldg 743 (LOB 3), room 156

    Hosted by: ''Ben Ocko, Shirish Chodankar, Milinda Abeykoon, Juergen Thieme and Guimei Wang''

  54. Physics Colloquium

    "Anomalies in Reactor Neutrinos"

    Presented by Chao Zhang, BNL

    Tuesday, July 11, 2017, 3:30 pm
    Large Seminar Room, Bldg. 510

    Nuclear reactors are one of the most intense, pure, controllable, cost-effective and well-understood sources of neutrinos. Reactor neutrinos have played a major role in the discovery of neutrinos and neutrino oscillations. However, recently there emerged a few anomalies from reactor neutrino experiments when compared with state-of-the-art model predictions. The anomalies include a 5.5% deficit of the integrated antineutrino flux, a discrepancy in the antineutrino prompt energy spectrum around 5 MeV, and a 7.8% deficit in the 235U antineutrino flux from the new fuel evolution analysis in the Daya Bay Experiment. In this talk, those anomalies and their implications will be discussed. A new reactor neutrino experiment, PROSPECT, is aiming to resolve the anomalies by precisely measuring the 235U antineutrino spectrum at a very short baseline. The status of the PROSPECT experiment will also be reported

  55. Office of Educational Programs Event

    "High School Research Program Begins"

    Monday, July 10, 2017, 8:30 am
    Hamilton Seminar Room, Bldg. 555

  56. Nuclear Theory/RIKEN Seminar

    "Holographic Pomeron: Scattering, saturation, entropy and black hole."

    Presented by Ismail Zahed, Stony Brook

    Friday, July 7, 2017, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: ''Heikki Mantysaari''

    I will discuss the general nature of the holographic Pomeron as a quantum QCD string exchange in both flat and curved AdS space for both pp and ep collisions at either large energies or small x. This description leads naturally to the concept of wee-strings and their distribution both in rapidity and transverse space. The holographic Pomeron carries intrinsic temperature and entropy, with the latter being identical to the recently reported entanglement entropy. I will show that this non-perturbative description of the Pomeron cross over to the the perturbative one, with a phase boundary dominated by string balls, i.e. long and massive strings near their intrinsic Hagedorn temperature. These string balls lead to a distribution of large multiplicity pp events that is in agreement with the one reported for pp collisions at the LHC. I will show that at low-x, the quantum string is so entangled that very weak string self-interactions can cause it to turn to a black hole. I will suggest that low-x saturation occurs when the density of wee-strings reaches the Bekenstein bound, with a proton size that freezes with increasing rapidity.

  57. Nuclear Theory/RIKEN Seminar

    "Probing Transverse Momentum Broadening in Heavy Ion Collisions"

    Presented by Feng Yuan, LBL

    Friday, June 30, 2017, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: 'Heikki Mantysaari'

    In this talk, we will discuss the dijet azimuthal de-correlation in relativistic heavy ion collisions as an important probe of the transverse momentum broadening effects in heavy ion collisions. We take into account both the soft gluon radiation in vacuum associated with the Sudakov logarithms and the jet PT-broadening effects in the QCD medium. We find that the Sudakov effects are dominant at the LHC, while the medium effects can play an important role at RHIC energies. This explains why the LHC experiments have not yet observed sizable PT-broadening effects in the measurement of dijet azimuthal correlations in heavy ion collisions. Future investigations at RHIC will provide a unique opportunity to study the PT-broadening effects and help to pin down the underlying mechanism for jet energy loss in a hot and dense medium.

  58. HET Seminar

    "Double Gauge Boson Production in the SM Effective Field Theory"

    Presented by Ian Lewis, University of Kansas

    Wednesday, June 28, 2017, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: '''Sally Dawson'''

  59. Nuclear Physics Seminar

    "Measurement of longitudinal flow correlations in 2.76 and 5.02 TeV Pb+Pb collisions with the ATLAS detector"

    Presented by Peng Huo, Stony Brook University

    Tuesday, June 27, 2017, 11 am
    Small Seminar Room, Bldg. 510

    Hosted by: 'Jin Huang'

    Longitudinal dynamics has recently become a topic of great interest in the study of ultra-relativistic heavy ion collisions. Measurement of the longitudinal fluctuations of the flow harmonic coefficients $v_n$ and event-plane angles $\Psi_n$ can provide a more complete picture of space-time evolution of the hot, dense medium formed in heavy ion collisions. Longitudinal flow decorrelations can be modeled with two contributions: magnitude fluctuations and event plane twist. However, existing observables do not separate these two effects. In this analysis, a new 4-particle correlator is used to separate the event-plane twist from magnitude fluctuations in 2.76 and 5.02 Pb+Pb collisions. Results show both effects have a linear dependence on pseudorapidity separation for $v_{2-5}$, and show a small but measurable variation with collision energy. The correlation of $\Psi_n $ of different order are also expected to have longitudinal fluctuations due to the non-linear mixing effects between lower and higher order flow harmonics. First measurement of such non-linear mode-mixing effects as a function of pseudorapidity is also presented. These result will help to constrain initial conditions along longitudinal direction and also help understand the longitudinal evolution of the fireball.

  60. Condensed-Matter Physics & Materials Science Seminar

    "Resonant inelastic X-ray scattering on "moderately correlated" quantum materials"

    Presented by L. Andrew Wray, New York University

    Thursday, June 22, 2017, 1 pm
    ISB Bldg. 734 Conf. Rm. 201 (upstairs)

    Hosted by: ''''Mark Dean''''

    The resonant inelastic X-ray scattering (RIXS) technique is best known for significant breakthroughs in the investigation of strongly correlated materials such as cuprates. However, the rapid advancement of RIXS spectrographs has made it increasingly attractive to apply the technique to a broad range of quantum materials outside of this comfort zone. This talk will review lessons learned from our recent measurements on material systems that feature a balance of correlated and itinerant physics, including VO2, the hidden order compound URu2Si2, and Prussian blue analogue battery electrodes. RIXS spectra enable the first observation of important collective modes for these systems, and provide a look into how correlated electron symmetries are melted - or persist! - in relatively itinerant and covalent environments. The data also highlight the need for improved theoretical modeling and higher photon throughput to achieve deeper insights.

  61. Condensed-Matter Physics & Materials Science Seminar

    "Tailoring Lattice and Charge at Complex Oxide Nanostructures and Interfaces"

    Presented by Xia Hong, University of Nebraska-Lincoln

    Tuesday, June 20, 2017, 11 am
    Bldg. 480, Conference Room

    Hosted by: 'Yimei Zhu'

    Capitalizing on the energy competition of charge itineracy with the strong electron-electron and electron-phonon couplings, nanoscale manipulation of the charge and lattice degrees of freedom in strongly correlated oxides can often lead to new functionalities that are inaccessible in the bulk form. In this talk, I will present our studies of the emerging phenomena at epitaxial correlated oxide nanostructures and hetero-interfaces that result from the nanoscale lattice and charge control. By creating nanoscale periodic depth modulation, we have achieved a 50-fold enhancement of the magnetic crystalline anisotropy in ultrathin colossal magnetoresistive (La,Sr)MnO3, which is attributed to a non-equilibrium strain distribution established in the nanostructures [1]. I will also discuss the intricate interplay between epitaxial strain and electric field effect in determining the correlated transport of the charge transfer type Mott insulator (Sm,Nd)NiO3 [2,3], and how the interfacial charge transfer between two correlated oxides can be exploited to effectively engineer the performance of ferroelectric-gated Mott transistors [4]. [1] A. Rajapitamahuni et al., PRL 116, 187201 (2016). [2] L. Zhang et al., JPCM 27, 132201 (2015). [3] L. Zhang et al., APL 107, 152906 (2015). [4] X. Chen et al., Adv. Mater, in press (2017).

  62. Condensed-Matter Physics & Materials Science Seminar

    "Laser-driven Pulsed Neutron Sources as a Potential Pool-side Characterization Tool for Nuclear Fuels"

    Presented by Sven Vogel, Los Alamos National Laboratory

    Monday, June 19, 2017, 1:30 pm
    ISB Bldg. 734, Conf. Rm. 201 (upstairs)

    Hosted by: '''Emil Bozin'''

    The unique advantages of neutrons for characterization of nuclear fuel materials [1] are applied at the pulsed spallation neutron source at LANSCE to accelerate the development and ultimately licensing of new nuclear fuel forms. Neutrons allow to characterize the crystallography of phases consisting of heavy elements (e.g. uranium) and light elements (e.g. oxygen, nitrogen, or silicon) [2]. The penetration ability in combination with comparably large (e.g. cm sized) beam spots provide microstructural characterization of typical fuel geometries for phase composition, strains, and textures from neutron diffraction. In parallel, we are developing energy-resolved neutron imaging and tomography with which we can complement diffraction characterization. This unique approach not only allows to visualize cracks, arrangement of fuel pellets in rodlets etc., but also characterization of isotope or element densities by means of neutron absorption resonance analysis [3]. Laser-driven pulsed neutron sources [4] have the potential to provide these capabilities "pool-side", e.g. at the Advanced Test Reactor at Idaho National Laboratory. Compared to proton accelerator driven spallation sources, requiring investments exceeding $1B, the investment cost for a laser-driven neutron source would be of the order of several $10M with the potential of similar flux to that of a smaller, earlier generation spallation neutron source. Compared to electron accelerator-driven neutron sources, the flux of a laser-driven source would be at least one order of magnitude higher. Compared to reactor neutron sources, the pulse structure of the laser-driven neutron source would enable unique characterization not possible with steady-state reactor neutrons. In this presentation, we provide an overview of our recent accomplishments in fuel characterization for accident-tolerant fuel consisting of uranium nitride/uranium silicide composite fuels as well as metallic fuels.

  63. Nuclear Theory/RIKEN Seminar

    "Better fitting through (fictitious) chemistry"

    Presented by Pasi Huovinen, Uniwersytet Wroclawski

    Monday, June 19, 2017, 10 am
    Small Seminar Room, Bldg. 510

    Hosted by: ''Heikki Mantysaari''

    One of the puzzles we have faced at the LHC is why the thermal models apparently cannot properly fit the yield of protons. I will explore how the fit improves if we assume that nucleon-antinucleon annihilations freeze-out way later than all other number changing processes or if strange particles freeze-out before non-strange particles, and how this affects the final particle distributions in hydrodynamical calculations.

  64. Nuclear Theory/RIKEN Seminar

    "Exploring the phase structure and dynamics of QCD"

    Presented by Jan Pawlowski, Heidelberg

    Friday, June 16, 2017, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: 'Heikki Mantysaari'

    The past years have seen tremendous progress in the description of Quantum Chromodynamics at vanishing and finite temperature and density with functional approaches, such as the functional renormalisation group or Dyson-Schwinger equations. Within these approaches QCD correlation functions of quarks, gluon and hadrons are computed non-perturbatively from first principles. In the talk I will discuss results for the phase structure of QCD at finite temperature and density, as well as for thermodynamical obserables such as the pressure and the trace anomaly. The approach is also applied to baryon number fluctuations. By now functional approaches also allow for a direct computation of transport coefficients in QCD. First results concern the temperature dependence of the shear viscosity over entropy ratio in Yang-Mills theory and QCD. The talk concludes with a discussion of the further prospects for our understanding of the phase structure and dynamics of QCD.

  65. Particle Physics Seminar

    "First Results from XENON1T"

    Presented by Dr. Fei Gao, Columbia University

    Thursday, June 15, 2017, 3 pm
    Small Seminar Room, Bldg. 510

    Hosted by: ''Xin Qian''

    Understanding the properties of dark matter particle is a fundamental problem in particle physics and cosmology. The search of dark matter particle scattering off nuclei target using ultra-low background detector is one of the most promising technology to decipher the nature of dark matter. The XENON1T experiment, which is a dual phase detector with ~2.0 tons of xenon running at the Gran Sasso Laboratory in Italy, is designed to lead the field of dark matter direct detection. Since November 2016, the XENON1T detector is continuously taking data, with a background rate of more than one order of magnitude lower than any current generation dark matter search experiment. In this talk, I will present the first dark matter search results from XENON1T. Details about the XENON1T detector as well as the data analysis techniques will also be covered.

  66. Condensed-Matter Physics & Materials Science Seminar

    "A model of chiral spin liquids with tunable edge states"

    Presented by Christopher Mudry, Paul Scherrer Institute, Switzerland

    Thursday, June 15, 2017, 1:30 pm
    Bldg. 734, ISB Conference Room 201 (upstairs)

    Hosted by: 'Alexei Tsvelik'

    We construct a quantum field theory in (2+1)-dimensional spacetime for strongly interacting Majorana fields that is amenable to a mean-field approximation. The mean-field phase diagram predicts the existence of two competing phases, one of which supports chiral non-Abelian topological order, while the other supports chiral Abelian topological order. The two mean-field phases are separated by a continuous phase transition. This quantum field theory captures the low-energy physics of quantum spin-1/2 localized on the sites of a lattice whose interactions are $SU(2)$ symmetric but break time-reversal symmetry. The lattice geometry can be interpreted as a one-dimensional stacking of two-leg ladders or as a bilayer of two square lattices. Both incompressible ground states can thus be thought of as chiral spin liquids in two-dimensional space supporting non-Abelian and Abelian topological order, respectively.

  67. HET/RIKEN Seminars

    "Searching for New Physics with Higgs Decays"

    Presented by Daniel Stolarski, Carleton University

    Wednesday, June 14, 2017, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: 'Pier Paolo Giardino'

  68. Particle Physics Seminar

    "Hadronically interacting Dark Matter, and a new mechanism for the Baryon Asymmetry, within QCD"

    Presented by Professor Glennys Reynolds Farrar, NYU

    Wednesday, June 14, 2017, 10 am
    Small Seminar Room, Bldg. 510

    Hosted by: 'Xin Qian'

    There may be a so-far-undiscovered neutral, stable particle composed of 6 quarks, denoted S, with mass m_S ~ 2 m_p. If so, the S is an excellent Dark Matter candidate. More generally, I will discuss how hadronic-strength interaction between DM and baryons can cause local DM to co-rotate with gas and stars, resulting in DM energy deposits below threshold for direct detection. DM-baryon interactions cause rotation curves to reflect baryonic density profiles, as observed in some galaxies, and can help alleviate some of the issues with CDM at small scales. An open question is whether the measured Ly-alpha power spectrum places an upper limit on the DM-baryon cross section, which is sufficiently robust and constraining to rule out the co-rotation scenario. The S-DM scenario suggests a new mechanism for producing the observed baryon asymmetry, and appears capable of naturally explaining the DM to baryon ratio.

  69. Physics Colloquium

    "Stable Sexaquark as Dark Matter"

    Presented by Professor Glennys Reynolds Farrar, NYU

    Tuesday, June 13, 2017, 3:30 pm
    Small Seminar Room, Bldg. 510

    Hosted by: 'Xin Qian'

    Dark Matter could be composed of an as-yet-undiscovered stable or essentially stable, neutral B=2 hadron composed of uuddss quarks. How such a particle, designated S for Sexaquark and to distinguish from the loosely bound di-Lambda called H-dibaryon, can be compatible with current knowledge is explained. The S is absolutely stable if m_S < 2 m_p+ 2 m_e. If m_S > 2 m_p+ 2 m_e but < m_p+m_e + m_Lambda, its lifetime could be longer than the age of the Universe. Experiments are proposed to discover and measure the mass of the proposed particle. To first approximation it behaves like standardl Cold Dark Matter, but some distinctive differences may help explain some puzzles about DM at galactic scales.

  70. Nuclear Theory/RIKEN Seminar

    "Gluon structure of hadrons and nuclei"

    Presented by Phiala Shanahan, MIT

    Friday, June 9, 2017, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: 'Heikki Mantysaari'

    I will present the results of recent lattice QCD studies of the gluon generalised form factors of both hadrons and light nuclei. The generalised transversity gluon distributions are of particular interest since they are purely gluonic; they do not mix with quark distributions at leading twist. In light nuclei they moreover provide a clean signature of non-nucleonic degrees of freedom. The goal of these studies is to provide QCD predictions to be tested at an electron-ion collider (EIC) designed to access gluon structure quantities including transverse-momentum dependent distributions (TMDs) and gluon generalised parton distributions (GPDs).

  71. RIKEN Lunch Seminar

    "Anomalies and Exact Results In Massive Quantum Chromodynamics"

    Presented by Zohar Komargodski, Stony Brook

    Thursday, June 8, 2017, 12:30 pm
    Building 510, Room 2-160

    Hosted by: 'Hiromichi Nishimura'

  72. Nuclear Physics Seminar

    "Anatomy of Azimuthal Angle Correlations in Large and Small Systems - Why the fuss?"

    Presented by Roy Lacey, Stony Brook University

    Tuesday, June 6, 2017, 11 am
    Small Seminar Room, Bldg. 510

    Hosted by: 'Oleg Eyser'

    Azimuthal momentum anisotropy measurements are ubiquitous at both RHIC and the LHC. However, there are pervasive misconceptions as to the mechanistic origin of this anisotropy in both small and large systems. In this talk, I will demonstrate how recent momentum anisotropy measurements, for a broad range of systems, have been leveraged to gain new mechanistic insights and to constrain the properties of the medium produced in these collisions. In particular, the role of final state effects versus initial state momentum domain effects in explanations of the measurements will be addressed.

  73. Nuclear Theory/RIKEN Seminar

    "Hydrodynamic Fluctuations in Heavy Ion Collisions"

    Presented by Derek Teaney, Stony Brook

    Friday, June 2, 2017, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: 'Heikki Mantysaari'

    We develop a set of kinetic equations for hydrodynamic fluctuations which are equivalent to nonlinear hydrodynamics with noise. The hydrokinetic equations can be coupled to existing second-order hydrodynamic codes to incorporate the physics of these fluctuations. We use the hydrokinetic equations to analyze thermal fluctuations for a Bjorken expansion, evaluating the contribution of thermal noise from the earliest moments and at late times. In the Bjorken case, the solution to the kinetic equations determines the coefficient of the first fractional power of the gradient expansion $ \sim 1/(\tau T)^{3/2}$ for the expanding system. Numerically, we find that the contribution to the longitudinal pressure from hydrodynamic fluctuations is larger than second-order hydrodynamics for typical medium parameters used to simulate heavy ion collisions. Subsequently we analyze the behaviour of hydrodynamic fluctuations of near the QCD critical point, and dilineate the relevance Kiblle-Zurek scaling relative to other physics. If time permits we will also describe how thermal fluctuations place a lower bound on the bulk viscosity of QCD. References: Y.~Akamatsu, A.~Mazeliauskas and D.~Teaney, ``A kinetic regime of hydrodynamic fluctuations and long time tails for a Bjorken expansion,'' [arXiv:1606.07742 [nucl-th]]. Y.~Akamatsu, D. Teaney, F. Yan, Y. Yin, ``Transitting the critical point,'' in progress.

  74. Environmental & Climate Sciences Department Seminar

    "Cloud radiative fraction: Determination by high resolution photography from the surface looking upward"

    Presented by Stephen E. Schwartz, Environmental & Climate Sciences Department

    Thursday, June 1, 2017, 11 am
    Conference Room Bldg 815E

    Clouds greatly affect short- and longwave radiation transfer in the atmosphere and consequently climate. Hence it is essential that the amount and radiative influences of clouds be accurately represented in climate models. The conventional measure of the amount of cloud in a grid cell is cloud fraction, CF, the fraction of the surface area covered by cloud. CF is a commonly reported meteorological quantity, with a long record of surface observations, greatly augmented in the past several decades by satellite observations. Global cloud fraction determined from satellite measurements has systematically increased with time, a consequence not of secular increase in cloud fraction but of an increase with time in the sensitivity of active and passive satellite instruments. Such a situation raises the question of whether CF can be defined and how well it can be measured. Commercially available digital cameras provide an unprecedented opportunity for detailed study of cloud structure from the surface, looking upward. Key attributes of such cameras include large number of pixels, (e.g., 3456 x 4608; 16 M pixel) yielding rich detail of spatial structure, high spatial resolution, and high dynamic range (16 bit in each of three color channels at visible wavelengths). In the work reported here two cameras were pointed vertically, typically with field of view FOV 21 × 29 mrad and 120 × 160 mrad, respectively, denoted here narrow field of view, NFOV, and wide field of view WFOV, corresponding, for cloud base at 1 km, to 21 × 29 m (NFOV) and 120 × 160 m (WFOV). For perspective, the FOV for the NFOV camera is 2 × 3 sun diameters and for the WFOV camera 11 × 15 sun diameters. Nominal angular dimension of a single pixel is 6 μrad for the NFOV camera and 34 μrad for the WFOV camera, corresponding, again for cloud height 1 km, to 6 mm and 34 mm, respectively. Such single-pixel resolution is some 3 to 5 orders of magnitude finer than that avai

  75. Particle Physics Seminar

    "Higgs boson properties: what we learn from run II of LHC"

    Presented by Andrei Gritsan, Johns Hopkins University

    Thursday, May 25, 2017, 3 pm
    Small Seminar Room, Bldg. 510

    Hosted by: 'Alessandro Tricoli'

    During the second run in 2015-2016, LHC delivered the number of proton-proton collisions far beyond expectation and at higher energy than in run I. We will review the very first results on the H boson properties based on the full dataset collected by CMS by now. We will go through the four main topics: H boson couplings to gauge bosons, couplings to fermions, self-couplings, and search for an extended Higgs sector. Prospects of some of these measurements through the end of run III and phase II of LHC will be discussed.

  76. RIKEN Lunch Seminar

    "Mixed Anomaly and Global Consistency"

    Presented by Yuya Tanizaki, RBRC

    Thursday, May 25, 2017, 12:30 pm
    Building 510, Room 2-160

    Hosted by: 'Hiromichi Nishimura'

    Symmetry and topology are powerful tools to study strongly interacting dynamics. In this talk, we will see that mixed 't Hooft anomaly and global consistency strongly constrains the possible low-energy dynamics in a simple quantum mechanical example. I will briefly explain the same idea is useful to study the phase diagram of bifundamental gauge theories at finite theta angles.

  77. HET/RIKEN Seminar

    "Cosmology in Mirror Twin Higgs and Neutrinos"

    Presented by Patrick Fox, Fermilab

    Wednesday, May 24, 2017, 2 pm
    Small Seminar Room, Bldg. 510

  78. Nuclear Physics Seminar

    "Searching for collectivity and testing the limits of hydrodynamics: results from the 2016 d+Au beam energy scan"

    Presented by Ron Belmont, University of Colorado Boulder

    Tuesday, May 23, 2017, 11 am
    Small Seminar Room, Bldg. 510

    Hosted by: 'Jin Huang'

    The standard picture of heavy ion collisions is that large systems (collisions of large nuclei like Au+Au and Pb+Pb) create a quark-gluon plasma that exhibits collective behavior indicative of nearly inviscid hydrodynamical evolution. Recently, data from small systems (collisions of a small projectile and a large target like d+Au and p+Pb) have been found to exhibit strikingly similar evidence for collective behavior. To further elucidate these results, RHIC delivered in 2016 a beam energy scan of d+Au collisions at 4 different energies: 200, 62.4, 39, and 19.6 GeV. In this talk we present a wide array of results from the Run16 d+Au BES and discuss the implications for collective behavior and the limits of applicability for hydrodynamics.

  79. Particle Physics Seminar

    "Tiny Bubbles in the Mine: New Results from the PICO-60 Dark Matter Detector"

    Presented by Dr. Eric Dahl, North Western

    Friday, May 19, 2017, 10 am
    Small Seminar Room, Bldg. 510

    Hosted by: 'Xin Qian'

    The PICO Collaboration builds bubble chambers for the direct detection of WIMP dark matter. These devices are unique among direct detection experiments both in the WIMP models they can probe and the backgrounds they face. The PICO collaboration has set consecutive world-leading direct-detection limits on the spin-dependent WIMP-proton cross section, most recently with a zero-background 1.2 ton-day exposure with a C3F8 target in the PICO-60 detector at SNOLAB. This result is significant not just because it reaches new WIMP parameter space, but also because it demonstrates our ability to eliminate the anomalous bubble nucleation background that limited past bubble chamber WIMP searches, opening the door for experiments at the ton scale and beyond. I will describe this new result from PICO, our immediate plans for new detectors at SNOLAB, and the broader role bubble chambers will play in the future of dark matter detection, including the new scintillating bubble chamber technology developed by my group at Northwestern.

  80. RIKEN Lunch Seminar

    "Probing quantum entanglement at the Electron Ion Collider"

    Presented by Dima Kharzeev, BNL and Stony Brook University

    Thursday, May 18, 2017, 12:30 pm
    Building 510, Room 2-160

    Hosted by: ''Hiromichi Nishimura''

  81. HET/RIKEN Seminars

    "Collider and Cosmological Signatures of a Strong Electroweak Phase Transition"

    Presented by Jonathan Kozaczuk, UMass Amherst

    Wednesday, May 17, 2017, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: ''Pier Paolo Giardino''

  82. Physics Colloquium

    "Direct Detection of sub-GeV Dark Matter"

    Presented by Rouven Essig, Stony Brook University

    Tuesday, May 16, 2017, 3:30 pm
    Large Seminar Room, Bldg. 510

    Hosted by: 'Andrei Nomerotski'

    Dark matter makes up 85% of the matter in our Universe, but we have yet to learn its identity. A broad array of search strategies are needed to probe for non-gravitational interactions between dark matter and ordinary matter. While most searches focus on Weakly Interacting Massive Particles (WIMPs) with masses between 1 GeV and 1 TeV, it is imperative to also consider other motivated dark matter candidates. In this talk, I will discuss dark matter with MeV-to-GeV masses, which is a theoretically and phenomenologically appealing possibility and presents a new frontier in the search for dark matter. I will highlight novel dark matter direct-detection strategies that can probe this under-explored mass range. I will describe how XENON10 data already probes dark matter with masses as low as a few MeV, and discuss improvements expected from new experiments using semiconductors or scintillators. This includes SENSEI, a new ultra-low-threshold silicon CCD detector, which is poised to probe vast new regions of parameter space in the next few years. I will also present a few simple benchmark models of MeV-to-GeV dark matter, and contrast direct-detection probes with searches at colliders and fixed-target experiments.

  83. Condensed-Matter Physics & Materials Science Seminar

    "Thin-Film Alchemy: Using Epitaxial Engineering to Unleash the Hidden Properties of Oxides"

    Presented by Darrell G. Schlom, Cornell University

    Monday, May 15, 2017, 1:30 pm
    Bldg. 734, ISB Conference Room 201 (upstairs)

    Hosted by: 'Ivan Bozovic'

    Guided by theory, unparalleled properties—those of hidden ground states—are being unleashed by exploiting large strains in concert with the ability to precisely control dimensionality and stabilize metastable phases in epitaxial oxide heterostructures. For example, materials that are not ferroelectric or ferromagnetic in their unstrained state can be transmuted into materials that are both at the same time. Similarly, new tunable dielectrics with unparalleled performance have been created as well as a new single-phase multiferroic material where ferroelectricity and strong magnetic ordering are coupled near room-temperature. These are just three examples of the unparalleled properties—those of hidden ground states—being unleashed in epitaxial oxide heterostructures utilizing thin film alchemy

  84. NSLS-II Friday Lunchtime Seminar Series

    "Status of SSRF and the Shanghai X-FEL Projects, and Efforts in Single Particle Imaging and Whole Cell Imaging with X-FELs"

    Presented by Thomas Earnest, Shanghai Synchrotron Radiation Facility

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

    Hosted by: 'Ben Ocko and Shirish Chodankar'

  85. RIKEN Lunch Seminar

    "The nucleon axial charge from Lattice QCD"

    Presented by Enrico Rinaldi, RBRC

    Thursday, May 11, 2017, 12:30 pm
    Building 510, Room 2-160

    Hosted by: ''Hiromichi Nishimura''

  86. Nuclear Theory/RIKEN Seminar

    "Probing nucleon substructure with Bayesian parameter estimation"

    Presented by Scott Moreland, Duke

    Friday, May 5, 2017, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: 'Heikki Mantysaari'

    Multi-particle correlations observed in small collision systems at top LHC energies exhibit signatures which are similar to those observed in large collision systems and generally attributed to the formation of a deconfined quark-gluon plasma (QGP). This suggests that even proton-proton and proton-lead collisions may produce small droplets of QGP which translate spatial inhomogeneities into final-state momentum anisotropies. A primary challenge in testing hydrodynamic descriptions of small collision systems is in modeling the initial stages of the collision. In this talk, I discuss recent efforts to apply Bayesian methodology to parametric descriptions of initial state physics. I show that such methods can be extended to smaller length scales which include partonic degrees of freedom and glean information regarding the fluctuating nature of the proton.

  87. HET Lunch Discussions

    "Standard Model EFT and Extended Scalar Sectors"

    Presented by Chris Murphy, BNL

    Friday, May 5, 2017, 12:15 pm
    Building 510, Room 2-160

    Hosted by: 'Christoph Lehner'

  88. Computational Science Initiative Event

    "Frontiers for High Performance Computing in Cancer Research"

    Presented by Dr. Eric A. Stahlberg, Frederick Nat Lab for Cancer Research

    Friday, May 5, 2017, 10 am
    Seminar Room, Bldg. 725

    Hosted by: 'Frank Alexander'

    Anticipated advances in high-performance computing are enabling exciting new areas of computational and data oriented cancer research. These frontiers are being explored in a unique collaboration between the US Department of Energy and the National Cancer Institute in the Joint Design of Advanced Computing Solutions for Cancer. While the three-year collaboration is still in its first year, the collaboration is providing tremendous insight into the promise and challenges of employing extreme scale computing to advance research in the challenging and complex problem of cancer. Challenged with the aim of providing predictive insight in areas such as tumor response to treatments, molecular level interactions, and even clinical outcomes, the collaborative effort advances the frontiers of cancer research and computing in both numerically-intensive and data-intensive applications, while providing insights into opportunities for the high-performance computing community overall.

  89. 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

    Thursday, May 4, 2017, 3 pm
    Small Seminar Room, Bldg. 510

    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.

  90. 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

    Thursday, May 4, 2017, 1:30 pm
    Bldg. 734, ISB Conference Room 201 (upstairs)

    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.

  91. RIKEN Lunch Seminar

    "Lattice study of gauge theory with multiple fermion representations"

    Presented by Ethan Neil, University of Colorado, Boulder and RBRC

    Thursday, May 4, 2017, 12:30 pm
    Building 510, Room 2-160

    Hosted by: 'Enrico Rinaldi'

    "There is long-standing theoretical interest in the behavior of a strongly-coupled gauge theory in the presence of multiple fermions charged under different representations of the gauge group. In addition to the question of whether generation of dynamically separated scales will occur, such theories appear commonly in UV realizations of composite Higgs models with partially composite top quarks. I will present a first lattice study of SU(4) gauge theory with fermions in each of the two lowest-lying representations, discussing the finite-temperature phase structure and low-lying spectrum. Connections to BSM physics through a particular composite Higgs model will also be made."

  92. Joint YITP/HET Seminar

    "Evidence for a ~17 MeV Particle in Rare Beryllium-8 Decays?"

    Presented by Tim Tait, UCI

    Wednesday, May 3, 2017, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: ''Amarjit Soni''

  93. Nuclear Theory/RIKEN Seminar

    "Analyticity in Spin and Causality in Conformal Theories"

    Presented by Simon Caron-Huot, McGill

    Friday, April 28, 2017, 2 pm
    Large Seminar Room, Bldg. 510

    Hosted by: ''Heikki Mantysaari''

    The conformal bootstrap aims to calculate scaling dimensions and correlation functions in various theories, starting from general principles such as unitarity and crossing symmetry. I will explain that local operators are not independent of each other but organize into analytic functions of spin, and I will present a formula, extending a classic one due to Froissart and Gribov in the early days of Regge theory, which quantifies the consequences of this fact. Applications will include a new way to solve crossing symmetry at large spin, as well as new bounds encoding bulk locality in theories with a gravity dual. Based on 1703.00278.

  94. Condensed-Matter Physics & Materials Science Seminar

    "Spin-liquids in novel triangular and kagome rare-earth magnets"

    Presented by Martin Mourigal, Georgia Tech

    Friday, April 28, 2017, 1:30 pm
    Bldg. 734, ISB Conference Room 201 (upstairs)

    Hosted by: '''Igor Zaliznyak'''

    Insulating magnets combining the effects of geometrical frustration with strong spin-orbit coupling offer a prime route to realize correlated quantum states with exotic ground-states and excitations. Spin-space anisotropy and bond-directional magnetic exchange interactions are naturally present in rare-earth oxides. One of the most celebrated consequence is the existence of classical and quantum "spin-ice" physics in rare-earth pyrochlores, materials in which magnetic ions occupy a three-dimensional network of corner-sharing tetrahedra. In this talk, I will present the discovery of distinct flavors of exotic magnetic matter in families of rare-earth oxides with two-dimensional kagome [1] and triangular [2] geometries. This experimental work relies on recent advances in materials synthesis and combines thermodynamic characterization with state-of-the-art neutron scattering experiments to unravel the classical or quantum nature of these newly discovered quasi-two-dimensional spin-liquids. [1] Emergent order in the kagome Ising magnet Dy3Mg2Sb3O14, J. A. M. Paddison, H. S. Ong, J. O. Hamp, P. Mukherjee, X. Bai, M. G. Tucker, N. P. Butch, C. Castelnovo, M. Mourigal, and S. E. Dutton, Nature Communications 7, 13842 (2016). [2] Continuous excitations of the triangular-lattice quantum spin liquid YbMgGaO4, J. A. M. Paddison, M. Daum, Z. L. Dun, G. Ehlers, Y. Liu, M. B. Stone, H. D. Zhou, and M. Mourigal, Nature Physics AOP (2016).

  95. Condensed-Matter Physics & Materials Science Seminar

    "Magnetometry Study of Underdoped Cuprate YBa2Cu3O6.55"

    Presented by Fan Yu, University of Michigan

    Friday, April 28, 2017, 11 am
    Bldg. 734, ISB. Conf. Rm. 168

    Hosted by: '''''''Qiang Li'''''''

    This talk would be focused on my study of the phase diagram of underdoped cuprate YBa2Cu3O6.55 using torque magnetometry as well as my exploration of extending magnetometry method into even higher magnetic fields (>45T) using pulsed magnet. The complex phase diagrams of cuprates are sometimes referred to as "competing orders", where a large variety of ordering tendencies are known to (co-)exist. Our experiment managed to reveal an anomaly on the magnetic susceptibility, which we believe was related to charge density wave transition. Particularly interesting is that this anomaly is observed in the strong diamagnetic regime where vortex liquid exists. We believe this should be considered as a direct experimental evidence for the picture of "competing orders". To further our understanding of the quantum vortex liquid, experiments at mK temperatures and at magnetic field exceeding 40 Tesla are necessary. During my PhD study, considerable amount of time was devoted to developing a reliable magnetometry method utilizing the pulsed magnet at NHMFL, Los Alamos. I would like to present my trail-and-error as well as the proposition of "time-delayed probe design", which should be able to bypass the inherent noise of a pulsed environment.

  96. Particle Physics Seminar

    "CP violation in neutrino oscillations and impact of new physics"

    Presented by Dr. Poonam Mehta

    Friday, April 28, 2017, 10 am
    Small Seminar Room, Bldg. 510

    Hosted by: 'Xin Qian'

    The study of CP violation addresses fundamental questions such as - are the laws of physics the same for matter and anti-matter. CP is a discrete symmetry of nature given by a product of two quantities : charge conjugation (C) and parity (P). Detecting leptonic CP violation is one of the most challenging goals in particle physics today. An attractive possibility to measure CP phase is via long baseline accelerator experiments such as Deep Underground Neutrino Experiment (DUNE). In this talk, we will show that clean extraction of CP violating phase becomes a formidable task in presence of new physics and one needs to devise ways to distinguish between standard paradigm and the new physics scenarios.

  97. Particle Physics Seminar

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

    Presented by Jim Annis, Fermilab

    Thursday, April 27, 2017, 3 pm
    Small Seminar Room, Bldg. 510

    Hosted by: 'Erin Sheldon'

  98. YITP/HET Joint Seminar

    "TBA"

    Presented by John Donoghue, U. Mass Amherst

    Wednesday, April 26, 2017, 3 pm
    YITP Seminar Room, Stony Brook University

  99. Physics Colloquium

    "Current Status of Neutrinoless Double Beta Decay Research"

    Presented by Bob McKeown, Jefferson Lab

    Tuesday, April 25, 2017, 3:30 pm
    Large Seminar Room, Bldg. 510

    Hosted by: 'Andrei Nomerotski'

    The observation of neutrinoless double beta decay would establish that neutrinos are Majorana fermions and would represent a discovery of profound importance: that lepton number is not conserved. There is currently a worldwide effort to search for neutrinoless double beta decay, using a variety of candidate isotopes and detector technologies. A subcommittee of the Nuclear Science Advisory Committee (NSAC) recently surveyed the field and the associated research and development needs. Based on the information provided to this subcommittee, I will present an overview of the present activity in this field and the prospects for the future.

  100. Nuclear Theory/RIKEN Seminar

    "Forward particle production in pA: implementing the NLO hybrid formalism"

    Presented by Tuomas Lappi, University of Jyväskylä

    Friday, April 21, 2017, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: 'Heikki Mantysaari'

    Single inclusive particle production cross sections in high energy hadron collisions at forward rapidity are an important benchmark process for the CGC picture of small x QCD. The process can be calculated in the "hybrid formalism", where a collinear large-x quark or gluon scatters off the dense color field of the target. Recent calculations at next-to-leading order in perturbation theory have not led to a stable physical result for the single inclusive cross section at high transverse momenta. The problem with these NLO calculations lies in the subtraction procedure for the soft "rapidity" divergence which must be absorbed into BK renormalization group evolution of the target. This talk discusses recent work to understand and resolve the problems with the subtraction procedure. In particular, we have recently implemented numerically the quark channel production cross section using a new rapidity factorization procedure proposed by Iancu et al. For a fixed coupling one does indeed obtain a physically meaningful cross section which is positive and reduces in a controlled way to previous leading order calculations. However, it is not yet clear how to generalize this to running coupling in a way that is fully consistent with previous leading order calculations in coordinate space.

  101. HET Lunch Discussions

    "The proton axial radius problem"

    Presented by Bill Marciano, BNL

    Friday, April 21, 2017, 12:15 pm
    Building 510, Room 2-160

    Hosted by: 'Christoph Lehner'

  102. Particle Physics Seminar

    "Searching for Our Milky Way's Dark Companions"

    Presented by Alex Drlica- Wagner, Fermilab

    Thursday, April 20, 2017, 3 pm
    Small Seminar Room, Bldg. 510

    Hosted by: ''Erin Sheldon''

    Our Milky Way galaxy is surrounded by a multitude of dwarf satellite galaxies. They are some of the oldest, least luminous, most metal poor, and most dark-matter-dominated objects known. These extreme objects provide a unique opportunity for testing the standard models of cosmology and galaxy formation. In addition, the relative proximity and large dark matter content of dwarf galaxies make them excellent systems for probing the fundamental properties of dark matter. Over the past two years, the unprecedented sensitivity of the Dark Energy Camera has allowed us to nearly double the known population of Milky Way satellites. These discoveries help address the "missing satellites problem" and can be used to test the particle nature of dark matter. However, they also raise new questions concerning the role of the Magellanic Clouds in the formation of the Milky Way's satellite population. I will summarize recent results, outstanding questions, and upcoming advances in the study of the Milky Way's dark companions.

  103. 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

    Thursday, April 20, 2017, 1:30 pm
    Bldg. 734, ISB Conference Room 201 (upstairs)

    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

  104. Particle Physics SB/BNL Joint Cosmo seminar

    "TBD"

    Presented by Kyle Story, Stanford

    Wednesday, April 19, 2017, 3 pm
    Stony Brook University

  105. Condensed-Matter Physics & Materials Science Seminar

    "Listening to the hydrodynamic noise of Dirac fluid in graphene"

    Presented by Kin Chung Fong, Raytheon BBN Technologies and Harvard University

    Tuesday, April 18, 2017, 1:30 pm
    Bldg. 734, ISB Conference Room 201 (upstairs)

    Hosted by: 'Qiang Li'

    Interactions between the Dirac fermions in graphene can lead to new collective behavior described by hydrodynamics. By listening to the Johnson noise of the electrons, we are able to probe simultaneously the thermal and electrical transport of the Dirac fluid and observe how it departs from Fermi liquid physics. At high temperature near the neutrality point, we find a strong enhancement of the thermal conductivity and breakdown of Wiedemann-Franz law in graphene. This is attributed to the non-degenerate electrons and holes forming a strongly coupled Dirac fluid. At lower temperatures beyond the hydrodynamic behavior, the Dirac fermions are in extreme thermal isolation with minute specific heat that can be exploited for ultra-sensitive photon detection. We will present our latest experimental result towards observing single microwave photons and explore its role in scaling up the superconducting qubit systems. Our model suggests the graphene-based Josephson junction single photon detector can have a high-speed, negligible dark count, and high intrinsic quantum efficiency for applications in quantum information science and technologies. Ref: Science 351, 1058 (2016)

  106. Nuclear Physics Seminar

    "Search for the Chiral Magnetic Effect at RHIC : challenges and opportunities"

    Presented by Prithwish Tribedy, BNL

    Tuesday, April 18, 2017, 11 am
    Small Seminar Room, Bldg. 510

    Hosted by: 'Jia Jiangyong'

    In this talk I will discuss about the ongoing and future efforts at RHIC towards the search for the Chiral Magnetic Effect (CME). I will focus on the recent STAR measurements of the charge separation across the reaction plane, a predicted signal of the Chiral Magnetic Effect. Although charge separation has been observed, it has been argued that the measured separation in A+A collisions can be explained by elliptic flow related backgrounds. I will discuss on the challenges in disentangling such background contributions from the signals of CME. I will also discuss on implications of the recent measurements of charge separation in p+A collisions towards the search for CME.

  107. Nuclear Theory/RIKEN Seminar

    "Effect of magnetic field on flow fluctuations in"

    Presented by Ajit M. Srivvastava

    Friday, April 14, 2017, 2 pm
    Small Seminar Room, Bldg. 510

    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.

  108. HET Lunch Discussions

    "Electroweak Wilson Coefficients from Lattice QCD"

    Presented by Mattia Bruno, BNL

    Friday, April 14, 2017, 12:15 pm
    Building 510, Room 2-160

    Hosted by: ''Christoph Lehner''

  109. Particle Physics Seminar

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

    Presented by Kaustubh Agashe, University of Maryland

    Thursday, April 13, 2017, 3 pm
    Small Seminar Room, Bldg. 510

    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.

  110. Condensed-Matter Physics & Materials Science Seminar

    "Electronic Squeezing of Pumped Phonons: Negative $U$ and Transient Superconductivity"

    Presented by Dante Kennes, Columbia University

    Thursday, April 13, 2017, 1:30 pm
    Bldg. 734, ISB Conference Room 201 (upstairs)

    Hosted by: '''Neil Robinson'''

    Advances in light sources and time resolved spectroscopy have made it possible to excite specific atomic vibrations in solids and to observe the resulting changes in electronic properties but the mechanism by which phonon excitation causes qualitative changes in electronic properties has remained unclear. Here we show that the dominant symmetry-allowed coupling between electron density and dipole active modes implies an electron density-dependent squeezing of the phonon state which provides an attractive contribution to the electron-electron interaction, independent of the sign of the bare electron-phonon coupling and with a magnitude proportional to the degree of laser-induced phonon excitation. Reasonable excitation amplitudes lead to non-negligible attractive interactions that may cause significant transient changes in electronic properties including superconductivity. The mechanism is generically applicable to a wide range of systems, offering a promising route to manipulating and controlling electronic phase behavior in novel materials.

  111. Nuclear Physics Seminar

    "Systematic study of hadron production in highly asymmetric collisions at PHENIX"

    Presented by Norbert Novitzky, Stony Brook University

    Tuesday, April 11, 2017, 11 am
    Small Seminar Room, Bldg. 510

    Hosted by: 'Jin Huang'

    The observation of long range correlations in highly asymmetric systems as in p+Pb and d+Au collisions suggests the creation of a medium with collective behavior. Single particle production has proven to be a valuable tool to probe the quark-gluon plasma formed in heavy ion collisions as it is sensitive to energy loss, modifications of the nuclear wavefunction. It is an open question whether the apparent medium in small-on-large collisions and the QGP in large-on-large collisions is indeed the same, as is the role of the dynamics of the projectile (nucleon) wavefunction. In order to address these questions with a systematic study of highly asymmetric collisions, the RHIC collider provided beams for p+Al, p+Au, d+Au and 3He+Au collisions. The hadron production as a function of transverse momentum (pT) and rapidity can provide us very useful information about the evolution of the initial state and medium formation with system size. We will present the neutral pion and charged hadron measurements at forward, mid- and backward rapidities and discuss the implications of the results.

  112. Nuclear Theory/RIKEN Seminar

    "Anisotropic dissipative fluid dynamics - foundations & applications in heavy-ion physics"

    Presented by Professor Dirk Rischke, Johann Wolfgang Goethe-Universität

    Friday, April 7, 2017, 2 pm
    Small Seminar Room, Bldg. 510

    Hosted by: ''Heikki Mantysaari''

    In collisions of heavy ions at ultrarelativistic energies, a system of hot and dense strongly interacting matter is created. This matter exhibits a surprisingly strong degree of collectivity, implying a short mean free path of its constituents and, consequently, a small shear viscosity-to-entropy density ratio. This allows to describe the evolution of the system using relativistic dissipative fluid dynamics. Dissipative fluid dynamics can be understood as an expansion around local thermodynamical equilibrium, corresponding to the ideal-fluid limit where dissipative corrections are absent. A short mean free path means that this expansion is well defined and converges sufficiently rapidly. Nevertheless, in the initial stage of a heavy-ion collision, space-time gradients of the fluid-dynamical fields (energy-momentum and net-charge densities) are so large that dissipative corrections to the ideal-fluid limit can become sizable. In this situation, novel approaches to relativistic dissipative fluid dynamics are called for. One such approach is anisotropic dissipative fluid dynamics, which is based on an expansion around an anisotropic non-equilibrium state (instead of local thermodynamical equilibrium, as in conventional dissipative fluid dynamics). In this talk, I present a derivation of the equations of motion of anisotropic dissipative fluid dynamics from the Boltzmann equation, using the method of moments. I also discuss how to resolve an ambiguity to close the system of equations of motion in the case when there are no corrections to the anisotropic state which constitutes the basis of the moment expansion.

  113. HET Lunch Discussions

    "Fuzzy Dark Matter from Infrared Confinement"

    Presented by Hooman Davoudiasl, BNL

    Friday, April 7, 2017, 12:15 pm
    Building 510, Room 2-160

    Hosted by: ''Christoph Lehner''

  114. Instrumentation Division Seminar

    "Next Generation Readout Electronics: Highly Integrated, High Performance and Low Cost Data Acquisition for Future Instrumentation Needs"

    Presented by Isar Mostafanezhad, Nalu Scientific, LLC

    Thursday, April 6, 2017, 2:30 pm
    Large Conference Room, Bldg. 535

    In this presentation, we discuss recent progress in high channel count data acquisition systems for large experiments. In recent years Nalu Scientific has established a new model for integration of readout electronics with detectors for HEP/NP applications. The most recent work has been involvement in the commissioning of the Belle II Time of Propagation Klong and Muon subdetectors at KEK in Japan. These innovations resulted in modern, modular, compact and high performance readout systems. Nalu Scientific, under multiple SBIR awards, has been working to commercialize these technologies to become available as off-the-shelf products for future experiments. We will cover: 1. Summary of Belle II TOP PID and KLM subdetectors 2. High performance, highly integrated, low cost readout 3. Current efforts in high resolution/ high performance timing 4. Specialized compact readout electronics for SiPMs

  115. A Special HET/RIKEN Lunch Seminar

    "The Road to Nuclear Physics from Standard Model"

    Presented by Zohreh Davoudi, MIT

    Thursday, April 6, 2017, 12:30 pm
    Building 510, Room 2-160

    Hosted by: ''Hiromichi Nishimura''

    At the core of nuclear physics is to understand complex phenomena occurring in the hottest and densest known environments in nature, and to unravel the mystery of the dark sector and other new physics possibilities. Nuclear physicists are expected to predict, with certainty, the reaction rates relevant to star evolutions and nuclear energy research, and to obtain the "standard" effects in nuclei to reveal information about the "non-standard" sector. To achieve such certainty, the field has gradually started to eliminate its reliance on the phenomenological models and has entered an era where the underlying interactions are "effectively" based on the Standard Model of particle physics, in particular Quantum Chromodynamics (QCD). The few-nucleon systems can now emerge directly from the constituent quark and gluon degrees of freedom and with only QCD interactions in play, using the numerical method of lattice QCD. Few-body observable, such as few-nucleon interactions and scattering amplitudes, as well transition amplitudes and reaction rates, have been the focus of this vastly growing field, as once obtained from QCD, and matched to effective field theories, can advance and improve the nuclear many-body calculations of exceedingly complex systems. This talk is a brief introduction to this program and its goals, with a great focus on the progress in few-body observables from QCD.

  116. HET Seminar

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

    Presented by Diptimoy Ghosh, Weizman

    Wednesday, April 5, 2017, 2 pm
    Small Seminar Room, Bldg. 510

    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.

  117. 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

    Tuesday, April 4, 2017, 11 am
    Small Seminar Room, Bldg. 510

    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.

  118. Instrumentation Division Seminar

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

    Presented by Zhehui Wang, LANL

    Friday, March 31, 2017, 2:30 pm
    Large Conference Room, Bldg. 535

    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.

  119. HET Lunch Discussions

    "A local factorization of the fermion determinant in lattice gauge theories"

    Presented by Leonardo Giusti, CERN

    Friday, March 31, 2017, 12:15 pm
    Building 510, Room 2-160

    Hosted by: 'Christoph Lehner'

  120. Particle Physics Seminar

    "neutrinoless double beta decay and nuclear structure theory"

    Presented by Professor Petr Vogel, Caltech

    Friday, March 31, 2017, 11 am
    Small Seminar Room, Bldg. 510

    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

  121. Particle Physics Seminar

    "Evaluation of reactor neutrino flux: issues and uncertainties"

    Presented by Professor Petr Vogel, Caltech

    Thursday, March 30, 2017, 3 pm
    Small Seminar Room, Bldg. 510

    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.

  122. 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

    Thursday, March 30, 2017, 1:30 pm
    ISB Bldg. 734, Conf. Rm. 201 (upstairs)

    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.

  123. RIKEN Lunch Seminar

    "The hadronic light-by-light contribution to muon g-2 from lattice QCD"

    Presented by Luchang Jin, BNL

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

    Hosted by: 'Enrico Rinaldi'

    The current measurement of muonic g-2 disagrees with the theoretical calculation by about 3 standard deviations. Hadronic vacuum polarization (HVP) and hadronic light by light (HLbL) are the two types of processes that contribute most to the theoretical uncertainty. The current value for HLbL is still given by models. We report our latest lattice calculation of hadronic light-by-light contribution to muon g-2 using our recent developed moment method. The connected diagrams and the leading disconnected diagrams are included. The calculation is performed on a 48^3 × 96 lattice with physical pion mass and 5.5 fm box size. We expect sizable finite volume and finite lattice spacing corrections to the results of these calculations which will be estimated in calculations to be carried out over the next 1-2 years.

  124. Particle Physics Seminar

    "Is there evidence for cosmic acceleration?"

    Presented by Subir Sarkar, Oxford University

    Thursday, March 30, 2017, 11 am
    Small Seminar Room, Bldg. 510

    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.

  125. Physics Colloquium

    "Physics in the complex domain"

    Presented by Carl Bender, Washington University

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

    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.

  126. 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

    Tuesday, March 28, 2017, 11 am
    Bldg. 734, ISB Conference Room 201 (upstairs)

    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.

  127. Nuclear Physics Seminar

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

    Presented by Niseem Magdy, Stony Brook University

    Tuesday, March 28, 2017, 11 am
    Small Seminar Room, Bldg. 510

    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).

  128. 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

    Monday, March 27, 2017, 10 am
    ISB Bldg. 734, Conf. Rm. 201 (upstairs)

    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)

  129. Nuclear Theory/RIKEN Seminar

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

    Presented by Carlos Naya, Durham

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

    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.

  130. Condensed-Matter Physics & Materials Science Seminar

    "Shining a light on high-Tc superconductivity"

    Presented by Peter Johnson, BNL

    Friday, March 24, 2017, 1:30 pm
    Bldg. 734, ISB Conference Room 201 (upstairs)

    Hosted by: '''Igor Zaliznyak'''

    TBD

  131. HET Lunch Discussions

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

    Presented by Pier Paolo Giardino, BNL

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

    Hosted by: 'Christoph Lehner'

  132. Particle Physics Seminar

    "Neutrino Interactions with Nuclei and Long-Baseline Experiments"

    Presented by Professor Ulrich Mosel, Giessen University

    Friday, March 24, 2017, 10 am
    Small Seminar Room, Bldg. 510

    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.

  133. 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)

  134. 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.

  135. 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.

  136. 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'

  137. 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'

  138. 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.

  139. 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

  140. 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''

  141. 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.

  142. 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'

  143. 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.

  144. 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.

  145. 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.

  146. 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.

  147. 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

  148. 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.

  149. 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.

  150. 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.

  151. 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

  152. 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''

  153. 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

  154. 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.

  155. Particle Physics Semiar SB/BNL Joint Cosmo Seminar

    "TBA"

    Presented by Will Farr, Birmingham

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

  156. 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''

  157. 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.

  158. 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.

  159. 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'

  160. 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.

  161. 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'

  162. 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'

  163. 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

  164. 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.

  165. 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'

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

    "TBA"

    Presented by Adrian Liu, Berkeley

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

  167. 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.

  168. 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.

  169. 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''

  170. 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'

  171. HET Seminar

    "TBA"

    Presented by Johannes Weber

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

    Hosted by: ''Mike Creutz''

  172. 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.

  173. 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

  174. 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'''

  175. 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

  176. 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''

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

    "TBA"

    Presented by Elisabeth Krause, SLAC

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

  178. 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.

  179. 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'

  180. 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.

  181. 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

  182. 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.

  183. Joint YITP/HET Seminar

    "muon colliders"

    Presented by Mario Greco, Frascati

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

  184. 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.

  185. 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''

  186. 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).

  187. 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).

  188. 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''

  189. 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.

  190. 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.

  191. 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.

  192. 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''

  193. 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.

  194. 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.

  195. 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.

  196. 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.

  197. 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.

  198. 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.

  199. 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.

  200. 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''

  201. 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

  202. 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.

  203. 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.

  204. 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.

  205. 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.

  206. 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'

  207. 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''

  208. 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.

  209. 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.

  210. 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'

  211. 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.

  212. 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.

  213. 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.

  214. 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.

  215. 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.

  216. 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.

  217. 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.

  218. 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.

  219. 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.

  220. 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.

  221. 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.

  222. 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

  223. 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.

  224. 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.

  225. 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

  226. 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.

  227. 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''

  228. 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.

  229. 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.

  230. 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'''

  231. 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.

  232. 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.

  233. 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.

  234. 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''

  235. 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.

  236. 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.

  237. 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''

  238. Particle Physics Seminar

    "TBA"

    Presented by Jo Bovy

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

    Hosted by: 'Neelima Sehgal'

  239. 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.

  240. 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.

  241. 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''

  242. 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

  243. 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.

  244. 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''

  245. 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.

  246. 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''

  247. 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.

  248. 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

  249. 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.

  250. 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.

  251. 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''

  252. 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.

  253. 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

  254. 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.

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