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JAN
27
Monday
HET Seminar
"New physics in rare decays"
Presented by Julian Heeck, UC Irvine
2:30 pm, Small Seminar Room, Bldg. 510
Monday, January 27, 2020, 2:30 pm
Despite its many successes, the Standard Model of particle physics cannot be the final description of nature at the most fundamental level. Additional elementary particles and interactions are an absolute necessity but have so far evaded our experimental efforts. I will highlight the importance of searches for processes that are forbidden within the Standard Model, as these make for clean signatures of new physics. Important examples are searches for lepton flavor violation and baryon number violation, which will be tested to unprecedented levels in upcoming experiments.
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JAN
28
Tuesday
Condensed-Matter Physics & Materials Science Seminar
"Effect of Zeeman coupling on the Majorana vortex modes in iron-based topological superconductors"
Presented by Pouyan Ghaemi, The City College of New York
1:30 pm, ISB Bldg. 734, Conf. Rm. 201 (upstairs)
Tuesday, January 28, 2020, 1:30 pm
Hosted by: Peter D. Johnson
In the superconducting regime of FeTe(1−x)Sex, there exist two types of vortices which are distinct by the presence or absence of zero energy states in their core. To understand their origin,we examine the interplay of Zeeman coupling and superconducting pairings in three-dimensional metals with band inversion. Weak Zeeman fields are found to suppress the intra-orbital spin-singlet pairing, known to localize the states at the ends of the vortices on the surface. On the other hand, an orbital-triplet pairing is shown to be stable against Zeeman interactions, but leads to delocalized zero-energy Majorana modes which extend through the vortex. In contrast, the finite-energy vortex modes remain localized at the vortex ends even when the pairing is of orbital-triplet form. Phenomenologically, this manifests as an observed disappearance of zero-bias peaks within the cores of vortices upon increase of the applied magnetic field. The presence of magnetic impurities in FeTe(1−x)Sex, which are attracted to the vortices, would lead to such Zeeman-induced delocalization of Majorana modes in a fraction of vortices that capture a large enough number of magnetic impurities. Our results provide a possible explanation to the dichotomy between topological and non-topological vortices recently observed in FeTe(1−x)Sex.
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JAN
30
Thursday
Environmental & Climate Sciences Department Seminar
"A NIST Perspective on Quantifying Aerosol Optical Properties: Metrology Challenges and Opportunities"
Presented by Jimmy Radney, NIST
11 am, Large Conference Room, Bldg. 490
Thursday, January 30, 2020, 11:00 am
Hosted by: Ernie Lewis
Atmospheric aerosols directly affect the earth's energy balance through the scattering and absorption of solar radiation. While aerosols are expected to have a net negative forcing (i.e. cooling), the actual magnitude of this effect remains highly uncertain due to physical, chemical, spatial and temporal variability. To complicate matters, strongly absorbing carbonaceous aerosols (i.e. black carbon, BC) exhibit a positive radiative forcing rivaling methane. A better understanding of the magnitude of these aerosol-radiation interactions requires a multi-pronged approach with fundamental metrology (e.g. instrumentation, methods, standards and calibrations) utilizing well-characterized systems under controlled conditions representing just one piece of the puzzle. Highlights of recent projects at the National Institute of Standards and Technology (NIST) will be presented including: 1) the characterization and use of a water-stabilized carbon black (CB) nanomaterial that mimics aged BC that can be used to calibrate aerosol instrumentation, 2) results from the first-ever photoacoustic spectrometer intercomparison study, 3) variability in the aerosol absorption spectra of highly-absorbing carbonaceous aerosols from a variety of sources and 4) aerosol absorption spectra of terrestrial mineral dusts and Martian soil simulants.
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JAN
30
Thursday
HET Seminar
"Phase transitions in the early Universe"
Presented by Djuna Croon, TRIUMF
2:30 pm, Small Seminar Room, Bldg. 510
Thursday, January 30, 2020, 2:30 pm
In anticipation of the next generation of gravitational wave experiments, I will discuss the opportunities for phenomenological studies of particle physics in the Early Universe. The focus of the talk will be on first order phase transitions in confining gauge theories. Such phase transitions may play an important role in explanations of the strong CP-problem, as well as in models of baryogenesis. I will discuss several such examples and their phenomenology.
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FEB
4
Tuesday
Nuclear Physics Seminar
"Global and local polarization of Lambda hyperons in Au+Au collisions"
Presented by Takafumi Niida
11 am, Small Seminar Room, Bldg. 510
Tuesday, February 4, 2020, 11:00 am
Hosted by: Rongrong Ma
The matter created in non-central heavy-ion collisions is expected to have an initial angular momentum carried by two colliding nuclei. Such an initial angular momentum would be transferred to the global polarization due to the spin-orbit coupling. The STAR Collaboration observed \Lambda global polarization in Au+Au collisions at \sqrt{s_{NN}} = 7.7—200 GeV, indicating a thermal vorticity of the system. The detailed structure of the vorticity field may be complicated. Local vorticity and consequently the particle polarization may arise from jets and/or collective flow. In this talk, recent results on the polarization along the beam direction expected from the elliptic flow will be presented and the physics implications will be discussed with theoretical calculations.
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FEB
6
Thursday
CFN Colloquium
"Progress in Trapped Ion Quantum Computing"
Presented by Prof. Jungsang Kim, Duke University
4 pm, CFN, Bldg 735, Seminar Room, 2nd Floor
Thursday, February 6, 2020, 4:00 pm
Hosted by: Chang-Yong Nam
Trapped ions are one of the leading candidates for realizing practically useful quantum computers. Introduction of advanced integration technologies to this traditional atomic physics research has provided an opportunity to convert a complex atomic physics experiment into a stand-alone programmable quantum computer. In this presentation, I will discuss the new enabling technologies that changes the perception of a trapped ion system as a scalable quantum computer, and the concrete progress made to date in this endeavor. Short Biography: Prof. Jungsang Kim's current research focus is practical realization of quantum computers. He received his B.S. degree from Seoul National University (1992) and his Ph.D. from Stanford University (1999), both in Physics. He worked at Bell Laboratories for five years, working on developing cutting-edge optical and wireless communication systems. He joined the Electrical and Computer Engineering department at Duke University in 2004, where he has worked on trapped ion quantum computing, high pixel-count imaging systems, and novel quantum device research. He has been serving as a principal investigator for many collaborative research projects on quantum computing and communications. In 2015, he co-founded IonQ, focusing on commercial development of ion trap based quantum computer.
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FEB
11
Tuesday
Physics Colloquium
"What ever happened to the WIMP of tomorrow?"
Presented by Philip 'Flip' Tanedo, UC Riverside
3:30 pm, Large Seminar Room, Bldg. 510
Tuesday, February 11, 2020, 3:30 pm
Hosted by: Gopolang Mohlabeng
The overwhelming observational evidence for the existence of dark matter is only matched by the awkward scarcity of information about what it might actually be. Laboratory searches for dark matter now appear to exclude many of the "weakly interacting massive particle" models that were favored by particle physicists for decades. Where does that leave the hunt for dark matter? If we've left the WIMP behind, what are we looking for? We give a brief, biased, and largely fictional history of the WIMP in order to establish what has and has not been excluded, and why it matters. This general-interest presentation grew out of discussions with astronomers who wanted to understand why some of their particle physics colleagues are "searching for WIMPs" while the others have decided to live in a "post-WIMP world".
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FEB
12
Wednesday
CSI Q Seminar
"Path to building quantum spin liquids and topological qubits within existing quantum hardware"
Presented by Dmitry Green, AppliedTQC
1:30 pm, Training Room, Bldg 725
Wednesday, February 12, 2020, 1:30 pm
Hosted by: Layla Hormozi
We solve the outstanding problem of how to build topological quantum spin liquids with physically accessible interactions. This result is at the nexus of theoretical physics and quantum technology, as one of its applications is to build topological qubits. We have discovered that multi-spin interactions that lead to quantum spin liquids can in fact be effectively realized by programming existing quantum hardware such as those made by D-Wave Systems. So, if nature does not give us the appropriate interactions, we will build them, instead.
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FEB
13
Thursday
Environmental & Climate Sciences Department Seminar
"Tropical Deep Convection and Entrainment in Idealized Cloud-Resolving Models"
Presented by Usama Anber, Environmental & Climate Sciences Dept (BNL)
11 am, Large Conference Room, Bldg. 490
Thursday, February 13, 2020, 11:00 am
Hosted by: Mike Jensen
Global Climate Models (GCMs) are depicted as the holy grail of climate science. However, they are far from reliably simulating the current and future climate. One of the components that represents a source of errors and biases in these models is the convective parametrization scheme and the ad-hoc treatment of deep convection and entrainment. In this talk, I will focus on two tropical atmospheric events that GCMs struggle to simulate: Amazonian deep precipitating convection, and the Madden Julian Oscillations. I will present how idealized cloud-resolving models (CRMs) coupled with simulated and forced large-scale circulation can capture the essential dynamics of these events. In particular, when diagnosed from the CRMs, I will show that entrainment is merely a response to the convective regime and cannot have a constant rate as GCMs suggest. If time allows, I will also point out to another potential source of biases in the simulated mean climate stemming from the representation of numerical noise damping in the model dynamical core.
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FEB
13
Thursday
RIKEN Lunch Seminar
"Shedding light on photon and dilepton spectral functions"
Presented by Greg Jackson, University of Bern
12 pm, Building 510, Room 2-160
Thursday, February 13, 2020, 12:00 pm
Hosted by: Yuta Kikuchi
Photons and dileptons offer themselves as 'clean' probes of the quark-gluon plasma because they are unlikely to reinteract once produced. Their emission rates are given via the vector channel spectral function, an object that can ultimately be reconstructed by analytic continuation of lattice data. To confront perturbative results with that data, the NLO corrections are needed in all domains that affect the associated imaginary-time correlator, namely for energies above, below and in the vicinity of the light cone. We summarize recent progress here and, to control an unavoidable snag, we also determine these corrections for the transverse and longitudinal polarizations separately. Our results should help to scrutinize direct spectral reconstruction attempts from lattice QCD.
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FEB
13
Thursday
NSLS-II Colloquium
"Subsurface Landscapes of Oxidation and Reaction in the Critical Zone"
Presented by Susan Brantley, Pennsylvania State University, PA
4 pm, Large Seminar Room, Bldg. 510
Thursday, February 13, 2020, 4:00 pm
Hosted by: John Hill
The globally ubiquitous mineral pyrite oxidizes even at low oxygen concentrations. As the most common crustal sulfide, pyrite reactivity impacts sulfur, iron, oxygen, and carbon budgets globally. We discovered that pyrite oxidizes completely at tens of meters depth even in low-porosity rocks in catchments in humid climates. As erosion exposes the pyrite to near-surface conditions in low porosity rocks, pore and fracture development is the main control on the rate of oxidative weathering. Between fractures, oxygen diffusion limits the weathering and oxidation is inferred to be largely abiotic because bacteria cannot enter rock matrix pores. Oxygen concentrations and erosion rates together can explain pyrite-derived sulfate fluxes in rivers to the ocean and may account for the presence or absence of pyrite in detrital sediments over Earth history.
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FEB
20
Thursday
Environmental & Climate Sciences Department Seminar
"Thermal acclimation of photosynthesis: patterns and diversity of plant responses to warming"
Presented by Danielle Way, Western University, Canada
11 am, Large Conference Room, Bldg. 490
Thursday, February 20, 2020, 11:00 am
Hosted by: Alistair Rogers
Climate change will increase global temperatures 3-4 ?C by 2100. This warming will affect photosynthesis, a temperature-sensitive process that helps dictate plant growth. Warming-induced shifts in photosynthesis also affect the global carbon cycle, mitigating or accelerating further climate change. Understanding how photosynthesis acclimates to future temperatures is therefore critical for accurately predicting the trajectory of future climate change, as well as for estimating plant productivity in a warmer world. I'll discuss how elevated growth temperatures impact photosynthesis, using meta-analyses, modeling and results from my lab, highlighting both what we know and the key questions that remain to be answered.
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FEB
24
Monday
BERA - Free Gym Membership Orientation 2020
"Orientation with Certified Personal Trainer"
Claire Ondrovic
5 pm, Gym, Bldg. 461
Monday, February 24, 2020, 5:00 pm
Hosted by: Christine Carter
Free Orientation 5-7pm on the following dates: Monday: 1/13, 2/24, 3/9, 4/20, 5/11, 6/15 Thursday: 1/23, 2/27, 3/19, 4/30, 5/21, 6/18
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FEB
26
Wednesday
Joint BNL/SBU HET Seminar
"A New Mask for An Old Suspect — Testing the Sensitivity of the Galactic Center Excess to the Point Source Mask"
Presented by Rouven Essig, Stony Brook
1:30 pm, Small Seminar Room, Bldg. 510
Wednesday, February 26, 2020, 1:30 pm
The Galactic center excess has lingered as a possible, but ambiguous, signal of new physics for several years. It has previously been argued that certain details of the excess emission imply that it likely originates from a population of point sources, but this remains a topic of vigorous debate. In this talk, I will report on my recent work, relying on a new point source catalog (obtained by the Fermi-LAT collaboration), that sheds light on this controversial topic. After giving some background on the excess, I will discuss various metrics that have been used to try to understand its true nature. I will show that the large majority of bright sources that were previously suggested to be members of the excess are indeed contained in the new Fermi-LAT point source catalog — and yet, despite masking out these sources (so that they cannot contribute to the excess), the excess remains just as bright in our new fit to the data. I will go on to discuss the implications of our findings for the two most popular interpretations of the excess and I will show some preliminary next steps to further clarify the nature of the excess.
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FEB
27
Thursday
BERA - Free Gym Membership Orientation 2020
"Orientation with Certified Personal Trainer"
Claire Ondrovic
5 pm, Gym, Bldg. 461
Thursday, February 27, 2020, 5:00 pm
Hosted by: Christine Carter
Free Orientation 5-7pm on the following dates: Monday: 1/13, 2/24, 3/9, 4/20, 5/11, 6/15 Thursday: 1/23, 2/27, 3/19, 4/30, 5/21, 6/18
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APR
8
Wednesday
CSI Q Seminar
"Quantum-driven classical optimization"
Presented by Helmut Katzgraber, Microsoft Research
1:30 pm, Training Room, Bldg 725
Wednesday, April 8, 2020, 1:30 pm
Hosted by: Layla Hormozi
The advent of the first useful quantum computing devices has resulted in an arms race with classical algorithms on traditional computing hardware. While near-term quantum devices might revolutionize, e.g., optimization and quantum chemistry, tackling many applications will directly depend on either hybrid or purely classical computing techniques. Inspired by these recent exciting developments, a variety of new classical algorithms have emerged. In this talk an overview on quantum inspired methods and their applications is given.
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APR
16
Thursday
Environmental & Climate Sciences Department Seminar
"Non-Equilibrium Aerosol Dynamics across Length Scales: Addressing a Few Contemporary Challenges"
Presented by Rajan Chakrabarty, Washington University, St. Louis
11 am, Large Conference Room, Bldg. 490
Thursday, April 16, 2020, 11:00 am
Hosted by: Ernie Lewis
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MAY
7
Thursday
Environmental & Climate Sciences Department Seminar
"Emergence of a New Chemical Regime at Whiteface Mountain: Growing Abundance of Water Soluble Organics in Cloud Water associated with a Growing Ion Imbalance"
Presented by Sara Lance, SUNY Albany
11 am, Large Conference Room, Bldg. 490
Thursday, May 7, 2020, 11:00 am
Hosted by: Ernie Lewis
