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JAN
17
Thursday
RIKEN Lunch Seminar
"Proton decay matrix elements on lattice"
Presented by Mr. Jun-sik Yoo, Stony Brook University
12 pm, Building 510, Room 2-160
Thursday, January 17, 2019, 12:00 pm
Hosted by: Enrico Rinaldi
Proton decay is one of possible signatures of baryon number violation, which has to exist to explain the baryon asymmetry and the existence of nuclear matter. Proton decay is one of natural implications of the Grand Unification Theory. After integrating out the high energy degrees of freedom, the baryon number violation operator that mediates proton decay can be found as the composite operator of standard model fields. We discuss the hadronic matrix elements of this BV operator made of three quarks and a lepton. We will start from the current experimental bound of proton lifetime. We present preliminary results of matrix element calculation done with the 2+1 dynamical flavor domain wall fermions at the physical point. We will discuss the proton decay channels that no matrix element has been calculated on the lattice.
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JAN
17
Thursday
SB/BNL Joint Cosmo seminar
"Cosmological results from cosmic shear measurements with KiDS+VIKING-450"
Presented by Arun Kannawadi Jayaraman, Leiden Observatory
3 pm, Small Seminar Room, Bldg. 510
Thursday, January 17, 2019, 3:00 pm
Hosted by: Chi-Ting Chiang
I will present the recent cosmic shear results from the combined optical+infrared data: KiDS+VIKING-450 (KV450). The tension between lensing and Planck measurements remains despite the systematics in the KV450 analysis being well-controlled. In this talk, I will mainly focus on the two main ingredients of KV450: redshift calibration and shape measurement. In particular, I show how redshift estimation is intricately coupled to shear measurement. The single largest source of uncertainty in the KV450 analysis comes from the error in shear calibration factors. Exploiting the full statistical power of future cosmic shear surveys such as Euclid and LSST will necessitate improvements to the accuracy with which the gravitational lensing signal is measured. I will end by briefly outlining some potential ideas to mitigate this uncertainty.
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JAN
18
Friday
Instrumentation Division Seminar
"Timing circuits for high-energy physics applications"
Presented by Jeffrey Prinzie, KU Leuven University, Belgium
10:30 am, Large Conference Room, Bldg. 535
Friday, January 18, 2019, 10:30 am
In the era of complex systems on chip (SoCs), clock and timing generation is required in nearly any application. These timing generators supply clock signals to digital modules, act as heartbeats for serial communication links or provide picosecond accurate reference information to time-interval sensors. Phase Locked Loops are the main building block that provide clock signals. However, in the high-energy physics community, ionizing radiation effects degrade these circuits significantly and produce soft-errors which can disturb an entire system. In this seminar, the application of these timing blocks in the high-energy physics are discussed together with the mitigation techniques for ionizing radiation.
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JAN
18
Friday
Nuclear Theory / RIKEN Seminar
"Chiral Vortical Effect For An Arbitrary Spin"
Presented by Andrey Sadofyev, Los Alamos National Lab
2 pm, CFNS Seminar Room 2-38
Friday, January 18, 2019, 2:00 pm
Hosted by: Niklas Mueller
Chiral effects attracted significant attention in the literature. Recently, a generalization of chiral vortical effect (CVE) to systems of photons was suggested. In this talk I will discuss the relation of this new transport to the topological phase of photons and show that, in general, CVE can take place in rotating systems of massless particles with any spin.
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JAN
18
Friday
Particle Physics Seminar
"Exploring the HEP frontier with the Cosmic Microwave Background and 21cm cosmology"
Presented by Laura Newburgh, Yale University
3 pm, Small Seminar Room, Bldg. 510
Friday, January 18, 2019, 3:00 pm
Hosted by: Anze Slosar
Current cosmological measurements have left us with deep questions about our Universe: What caused the expansion of the Universe at the earliest times? How many standard model particles are there? What is the underlying nature of Dark Energy and dark matter? New experiments like CMB-StageIV, Simons Observatory, and CHIME are poised to address these questions through measurements of the polarized Cosmic Microwave Background and 3-dimensional maps of structure. In this talk, I will describe efforts in the community to deploy enormous experiments that are capable of turning CMB measurements into probes of high energy particle physics. I will also discuss how we can broaden the potential science returns by including 21 cm measurements of large scale structure as a new means to probe Dark Energy with experiments like CHIME and HIRAX.
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JAN
23
Wednesday
Condensed-Matter Physics & Materials Science Seminar
"Recent Progress in Non-perturbative methods for QFTs"
Presented by Lorenzo Vitale, Boston University
1:30 pm, ISB Bldg. 734 Conf. Rm. 201 (upstairs)
Wednesday, January 23, 2019, 1:30 pm
Hosted by: Alexei Tsvelik
Quantum field theories (QFT) are notoriously hard to solve in the strongly coupled regime, and few tools are available in space dimension larger than one. In this talk I discuss recent progress and ideas in characterizing certain QFTs in dimension d >= 1, based on the Hamiltonian Truncation and S-matrix bootstrap techniques. Some of the applications I will mention are Landau-Ginzburg theories and the Chern-Simons-matter theories.
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JAN
23
Wednesday
Instrumentation Division Seminar
"A Roadmap for the Best PMTs and SiPM in Physics Research"
Presented by Razmik Mirzoyan, Max Planck Institute for Physics, Germany
2:30 pm, Large Conference Room, Bldg. 535
Wednesday, January 23, 2019, 2:30 pm
Photomultiplier Tubes (PMT) are the most wide spread detectors for measuring fast and faint light signals. In cooperation with the companies Hamamatsu Photonics K.K. (Japan) and Electron Tubes Enterprises Ltd. (England) we pursued an improvement program for the PMTs for the Cherenkov Telescope Array (CTA) project. CTA is the next major Imaging Atmospheric Cherenkov Telescopes (IACT) array for ground-based very high energy gamma-ray astrophysics. A total of ∼100 telescopes of sizes of 23m, 12m and 4m in diameter will be built in northern and southern hemispheres. The manufacturers succeeded producing 1.5′ PMTs of enhanced peak quantum efficiency of ∼38-42 % and after pulsing below 0.02% (threshold ≥ 4 photoelectrons). The novel 1.5′ PMTs have the world-wide best parameters. It is interesting to compare the performance of PMTs with the current generation of SiPMs. In the imaging camera of the MAGIC IACT, consisting of 1039 PMTs, since many months we are operating composite clusters of SiPMs from the three well-known manufacturers. A critical comparison of these two types of sensors will be presented. Prospects for further significant improvements of PMTs and SiPMs will be discussed, also in the frame of the supported by the EU SENSE Roadmap for the best fast light sensors.
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JAN
24
Thursday
Environmental & Climate Sciences Department Seminar
"WRF-Solar: Model overview and ongoing developments"
Presented by Pedro Jiminez Munoz, NCAR
11 am, Conference Room Bldg 815E
Thursday, January 24, 2019, 11:00 am
Hosted by: Yangang Liu
The WRF-Solar model is an augmentation of the Weather Research and Forecasting (WRF) model specifically designed for solar energy applications. The developments have focused on improving the representation of the aerosol-cloud-radiation physics. In this direction, WRF-Solar includes a fast radiative transfer parameterization to provide surface irradiance forecast only limited by the model time step; an improved representation of the aerosol-radiation feedback (aerosol direct effect); incorporation of the cloud-aerosol feedbacks (aerosol indirect effects); and improved cloud-radiation feedbacks. During this seminar I will provide an overview of the WRF-Solar model and present evaluations that illustrate the benefits of the augmentations. Ongoing developments including a better cloud initialization and extending the model to provide probabilistic forecasts will be also discussed.
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JAN
24
Thursday
RIKEN Lunch Seminar
"Quarkonium production in heavy ion collisions: open quantum system, effective field theory and transport equations"
Presented by Xiaojun Yao, Duke University
12 pm, Building 510, Room 1-224
Thursday, January 24, 2019, 12:00 pm
Hosted by: Yuta Kikuchi
In this talk, I will present a connection between two approaches of studying quarkonium dynamics inside quark-gluon plasma: the open quantum system formalism and the transport equation. I will discuss insights from the perspective of quantum information. I will show that under the weak coupling and Markovian approximations, the Lindblad equation turns to a Boltzmann transport equation after a Wigner transform is applied to the system density matrix. I will demonstrate how the separation of physical scales justifies the approximations, by using effective field theory of QCD. Finally, I will show some phenomenological results based on the derived transport equation.
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JAN
25
Friday
NSLS-II Friday Luncheon Seminar
"EDRIXS: An open source toolkit for simulating spectra of resonant inelastic x-ray scattering"
Presented by Yilin Wang, Condensed Matter Physics & Material
12 pm, NSLS-II, Bldg. 743 Rm 156
Friday, January 25, 2019, 12:00 pm
Hosted by: Ignace Jarrige
In this talk, we present an open source toolkit (dubbed EDRIXS) to facilitate the simulations of RIXS spectra of strongly correlated materials based on exact diagonalization (ED) of certain model Hamiltonians. The model Hamiltonian can be from a single atom, small cluster or Anderson impurity model, with model parameters from density functional theory plus Wannier90 or dynamical mean-field theory calculations. The spectra of x-ray absorption spectroscopy (XAS) and RIXS are then calculated using Krylov subspace techniques. This toolkit contains highly efficient ED, XAS and RIXS solvers written in modern Fortran 90 language and a convenient Python library used to prepare inputs and set up calculations. We first give a short introduction to RIXS spectroscopy, and then we discuss the implementation details of this toolkit. Finally, we show several examples to demonstrate its usage.
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JAN
29
Tuesday
Condensed-Matter Physics & Materials Science Seminar
"Strongly-correlated systems: Controllable field-theoretical approach"
Presented by Igor Tupitsyn, University of Massachusetts Amherst
1:30 pm, ISB Bldg. 734, Conf. Rm. 201 (upstairs)
Tuesday, January 29, 2019, 1:30 pm
Hosted by: Alexei Tsvelik
Accurate account for interactions in theoretical models for strongly correlated many-body systems is the key for understanding real materials and one of the major technical challenges of modern physics. To accept this challenge, new and more effective methods, capable of dealing with interacting systems/models in an approximation-free manner, are required. One of such methods is the field-theoretical Diagrammatic Monte Carlo technique (DiagMC). While a conventional Quantum Monte Carlo samples the configuration space of a given model Hamiltonian, the DiagMC samples the configuration space of the model-specific Feynman diagrams and obtains final results with controlled accuracy by accounting for all the relevant diagrammatic orders. In contrast to conventional QMC, it does not suffer from the fermionic sign problem and can be applied to any system with arbitrary dispersion relation and shape of the interaction potential (both doped and undoped). In the first part of my talk I will introduce the technique, based on its bold-line (skeleton) implementation, and benchmark it against known results for the problem of semimetal-insulator transition in suspended graphene. In the second part I will briefly demonstrate its applications to various strongly-correlated systems/problems (stability of the 2d Dirac liquid state against strong long-range Coulomb interaction; interacting Chern insulators; phonons in metals; 1d chain of hydrogen atoms; uniform electron gas (jellium model), optical conductivity, etc).
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JAN
31
Thursday
Environmental & Climate Sciences Department Seminar
"What can we learn from cloudy convection in a box? Laboratory meets LES with cloud microphysics"
Presented by Raymond Shaw, MTU
11 am, Conference Room Bldg 815E
Thursday, January 31, 2019, 11:00 am
Hosted by: Fan Yang
Inspired by early convection-tank experiments (e.g., Deardorff and Willis) and diffusion-chamber experiments, we have developed a cloud chamber that operates on the principle of isobaric mixing within turbulent Rayleigh-Bénard convection. The "Pi cloud chamber" has a height of 1 m and diameter of 2 m. An attractive aspect of this approach is the ability to make direct comparison to large eddy simulation with detailed cloud microphysics, with well characterized boundary conditions, and statistical stationarity of both turbulence and cloud properties. Highlights of what we have learned are: cloud microphysical and optical properties are representative of those observed in stratocumulus; aerosol number concentration plays a critical role in cloud droplet size dispersion, i.e., dispersion indirect effect; aerosol-cloud interactions can lead to a condition conducive to accelerated cloud collapse; realistic and persistent mixed-phase cloud conditions can be sustained; LES is able to capture the essential features of the turbulent convection and warm-phase cloud microphysical conditions. It is worth considering what more could be learned with a larger-scale cloudy-convection chamber. Turbulence Reynolds numbers and Lagrangian-correlation times would be scaled up, therefore allowing more enhanced role of fluctuations in the condensation-growth process. Larger vertical extent (of order 10 m) would approach typical collision mean free paths, thereby allowing for direct observation of the transition from condensation- to coalescence-growth. In combination with cloudy LES, this would be an opportunity for microphysical model validation, and for synergistic learning from model-measurement comparison under controlled experimental conditions.
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JAN
31
Thursday
CFN Colloquium
""Fermi systems and quantum computing""
Presented by Antonio Mezzacapo, Theory of Quantum Computing and Information, IBM T.J. Watson Research Center
4 pm, CFN, Bldg 735, Seminar Room 2nd Floor
Thursday, January 31, 2019, 4:00 pm
Hosted by: Deyu Lu (CFN) / Michael McGuigan (CSI)
Solving correlated Fermi systems is a problem of ubiquitous importance in the fields of chemistry, materials science and fundamental interactions. Quantum computers can help addressing this type of challenges, provided that descriptions of Fermi systems are loaded onto a set of qubits. In this talk I will review methods to represent Fermi quantum states and interactions onto a set of qubits, how to optimize mapping procedures, and how these methods are used to perform computations on quantum hardware. I will then introduce connections between such mappings and stabilizer codes, showing that adequate encodings can account for the correction of single-qubit errors. Finally, I will show how the tools presented can have an impact on classical numerical methods.
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FEB
5
Tuesday
Workshop
"Cornell Tick Workshop"
Marie Boulier, Cornell Cooperative of Suffolk County
9 am, Berkner Hall, Room B
Tuesday, February 5, 2019, 9:00 am
Hosted by: Tim Green
An Educational Forum for Educators, Parents, the Agricultural Tourism Business, Agricultural Producers, and the General Public
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FEB
7
Thursday
Particle Physics Seminar
"Probing New Physics and the Nature of the Higgs Boson at ATLAS"
Presented by Lailin Xu, University of Michigan
3 pm, Small Seminar Room, Bldg. 510
Thursday, February 7, 2019, 3:00 pm
Hosted by: Alessandro Tricoli
The long-sought Higgs boson discovered at the LHC completes the Standard Model of the particle physics. During the last six years, substantial achievements have been made to probe the nature of the Higgs boson. Participle physics is however at an impasse: deep mysteries of the Electroweak symmetry breaking remain unanswered, and long-awaited new physics phenomena beyond the SM have not shown up yet. In this talk, I start with a brief overview on the current profile of measurements of the Higgs boson properties and couplings. I then present Higgs measurements in the four-lepton channel, and how we use the Higgs boson as a portal in the quest for new physics. In the end, I discuss the prospect of the Higgs measurements including the Higgs self-coupling at future colliders.
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FEB
14
Thursday
Environmental & Climate Sciences Department Seminar
"TRacking Aerosol Convection interactions ExpeRiment (TRACER) - An upcoming ARM field campaign"
Presented by Michael Jensen, Environmental and Climate Sciences Department, Brookhaven National Laboratory
11 am, Conference Room Bldg 815E
Thursday, February 14, 2019, 11:00 am
Despite their climatic importance, multi-scale models continue to have persistent biases produced by insufficient representation of convective clouds. To increase our understanding of convective cloud lifecycles and aerosol-convection interactions, the TRacking Aerosol Convection interactions ExpeRiment (TRACER) will take place in the Houson, TX region from April 2021 through April 2022 with an intensive observation period from June to September 2022. TRACER (currently) includes the deployment of the ARM Mobile Facility, a C-band scanning polarimetric radar, and additional aerosol and atmospheric state measurements within existing surface meteorology, air quality and lightning dection neworks. A unique component of TRACER is that a large number of individual, isolated convective cells will be tracked and measured in high spatial and temporal resolution for the purposes of: (i) Characterizing and linking convective cloud kinematic and microphysical lifecycles, (ii) Quantifying environmental thermodynamic and kinematic controls on convective lifecycle properties, and (iii) Isolating and quantifying the impacts of aerosol properties on convective cloud kinematic and microphysical evolution. The seminar will present the scientific motivation for the TRACER campaign, details on the deployment strategies, and evolving opportunities for participation. The unique combination of cloud, precipitation, lightning, aerosol, and atmospheric state measurements associated with tracked convective cells will ultimately improve our understanding of the convective cloud lifecycle and its interaction with individual environmental factors such that improved, next generation cumulus, microphysics, turbulence, and aerosol parameterizations can be designed.
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FEB
14
Thursday
NSLS-II Collquium
"Resonant x-ray scattering from soft materials as a probe of molecular orientation fluctuations at the nanoscale"
Presented by Noel A. Clark, University of Colorado, Boulder
4 pm, Large Seminar Room, Bldg. 510
Thursday, February 14, 2019, 4:00 pm
Hosted by: John Hill
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MAR
7
Thursday
Environmental & Climate Sciences Department Seminar
"The Characteristics of Mesoscale Convective Systems as Revealed by Radar Wind Profilers"
Presented by Die Wang, Environmental and Climate Sciences Department, Brookhaven National Laboratory
11 am, Conference Room Bldg 815E
Thursday, March 7, 2019, 11:00 am
Hosted by: Scott Giangrande
