Wednesday, February 19, 2020, 10:00 am

Hosted by: QOL/BERA/Recreation

Bring the kids to play and the parents will have coffee, pastry and socialize! 10am-12 noon at 317 Rec Hall in the Apartment area.

Wednesday, February 19, 2020, 2:00 pm

Hosted by: Nikhil Karthik

In this talk we review indications of an infrared gluon mass in different nonperturbative approaches and discuss its dynamical generation in a Gribov-Zwanziger model. We compute in particular the one-loop effective potential of the model in the recently-established BRST-invariant setup which guarantees gauge-parameter independence of the generated mass scales.

Wednesday, February 19, 2020, 2:30 pm

Hosted by: Peter Denton

Thursday, February 20, 2020, 11:00 am

Thursday, February 20, 2020, 12:00 pm

Hosted by: Akio Tomiya

It is known that quantum phase transitions occur in the process of quantum annealing. The order of phase transition and computational efficiency are closely related with each other. Quantum computation starts with a non-entangled state and evolves into some entangled states, due to many body interactions and the dynamical delocalization of quantum information over an entire system's degrees of freedom (information scrambling). It is common to diagnose scrambling by observing the time evolution of single qubit Pauli operators with an out-of-timeorder correlator (OTOC). We aim at establishing a method to clarify those relations between phase transitions and scrambling by OTOCs. Using the p-spin model, we diagnose quantum phase transitions associated with quantum annealing and reverse annealing. In addition we provide a novel Majorana fermion model in which non-stoquastic dynamics of annealing can turn a first-order phase transition into a second-order phase transition. We also show that these phase transitions can be diagnosed by the OTOCs.

Thursday, February 20, 2020, 3:00 pm

Hosted by: Hanyu Wei

Neutrino oscillations have been established as an energy and distance dependent phenomena, beyond the Standard Model of Particle Physics. However, a number of key questions remain, which have implications for our understanding of the origin and development of our Universe. The Deep Underground Neutrino Experiment (DUNE), which is currently in the planning stage, has the potential to answer these outstanding questions and make measurements of the other parameters with unprecedented precision. This talk gives an overview of the DUNE sensitivity to oscillation parameters, and describes a program of research aimed at reducing systematic uncertainties, and achieving DUNE's physics goals.

Thursday, February 20, 2020, 4:00 pm

Hosted by: Abha Rajan

Recent progress in an ongoing program of evaluating transverse momentum-dependent (TMD) observables in the proton within Lattice QCD is reviewed. These lattice calculations are based on a definition of TMDs through hadronic matrix elements of quark bilocal operators, including an appropriate gauge connection between the quarks. Results presented include data on the Sivers and Boer-Mulders effects, highlighting the decisive role of the gauge connection in encoding information about the struck quark in a deep inelastic scattering process. First lattice data obtained directly at the physical pion mass are exhibited, and an exploratory outlook on extracting the dependence of the Sivers shift on the quark momentum fraction x is given.

Friday, February 21, 2020, 10:00 am

Hosted by: Oleg Gang

DNA is a unique polymer. It is the information storage molecule of all known life forms, and can be used to build up almost arbitrary structures and patterns from DNA. These structures can site-specifically be functionalized with a large variety of inorganic nanoparticles, small molecules or large biomolecules such as proteins and antibodies. Our group is leveraging this programmability to engineer nanoarchitectures and tools for applications in Biophysics, Molecular Biology, Nanophotonics and Nanomedicine. In this seminar, I will present a the precise, robust and high-yield assembly of gold nanoparticles on DNA origami templates. This enabled us to synthesize a self-assembled a plasmonic particle chain waveguide that was capable of an efficient energy propagation towards a nano diamond. Next, I will demonstrate a block copolymer-based strategy to protect DNA-based structures from nucleases and low salt conditions for nanomedical applications, and a "next-generation" DNA synthesis method to cost-effectively amplify oligonucleotides from oligonucleotide libraries. More information: https://www.kent.edu/physics/profile/thorsten-lars-schmidt

Friday, February 21, 2020, 12:15 pm

Friday, February 21, 2020, 2:00 pm

Hosted by: Nikhil Karthik

We develop two approaches to the problem of soft fragmentation of hadrons in a gauge theory for high energy processes. The first approach directly adapts the standard resummation of the parton distribution function's anomalous dimension (that of twist-two local operators) in the forward scattering regime, using kT-factorization and BFKL theory, to the case of fragmentation function by exploiting the mapping between the dynamics of eikonal lines on transverse-plane to the celestial-sphere. Critically, to correctly resum the anomalous dimension of the fragmentation function under this mapping, one must pay careful attention to the role of regularization, despite the manifest collinear or infra- red finiteness of the BFKL equation. The anomalous dependence on energy in the celestial case, arising due to the mismatch of dimensionality between positions and angles, drives the differences between the space-like and time-like anomalous dimension of parton densities, even in a conformal theory. The second approach adapts an angular-ordered evolution equation, but working in 4 − 2epsilon dimensions at all angles. The two approaches are united by demanding that the anomalous dimension in 4 − 2epsilon dimensions for the PDF determines the kernel for the angular-ordered evolution to all orders.

Monday, February 24, 2020, 11:00 am

Hosted by: Alexei Tsvelik

In this talk I am going to touch two interesting strongly-correlated problems: Resonant inelastic x-ray scattering (RIXS) in metals and Spin fermion (SF) model. RIXS is a very promising technique for studying collective excitations in condensed matter systems. However, extraction of information from the RIXS signal is a difficult task and the standard approach to solution of RIXS problem is based on approximations that are inaccurate in metals (short-range/contact potentials and non-interacting Fermi-sea). Simultaneously, the SF model has a wide range of applications in the physics of cuprates and iron-based superconductors. However, all developments and applications of the SF model are also based on various, often uncontrollable, approximations. In my talk I am going to address both problems within the general "field-theoretical approach to strongly-correlated problems" framework. In the first part I will consider the RIXS in metals problem within a diagrammatic approach that fully respects the long-range Coulomb nature of interactions between all charged particles. In particular, I will demonstrate how the single-plasmon dispersion can be extracted from the multi-excitation RIXS spectra. In the remaining time I will briefly discuss how to deal with the SF model in the approximation-free manner by employing the Diagrammatic Monte Carlo technique, combining the advantages of Feynman diagrammatic techniques and Quantum Monte Carlo simulations. I will also show what one can get in the first skeleton order – in the widely used in materials science GW approximation.

Tuesday, February 25, 2020, 11:00 am

Hosted by: Jiangyong Jia

In relativistic heavy-ion collisions, correlations of hadrons with opposite quantum numbers provide insight into general charge creation mechanisms, the time scales of quark production, collective motion of the Quark Gluon Plasma (QGP), and re-scattering in the hadronic phase. The longitudinal and azimuthal widths of general charge balance functions for charged pion (??±), kaon (??±) and (anti-)proton (??/??¯) are used to examine the two-wave quark production scenario recently proposed to explain quark-antiquark productions within the QGP, which predicts a large increase in up and down quark pairs relative to strange quark pairs around the time of hadronization. Balance function as a function of relative azimuthal angle is a good probe to the diffusion effect, which is a signature of the QGP. In addition, the balance function integrals measure hadron pairing probabilities, which provide a key constraint for hadron productions in models. Furthermore, balance function is also a key observable to study net-proton fluctuations and the Chiral Magnetic Effect (CME). In this talk, I will present a state-of-the-art overview on experimental measurements of balance function by STAR and ALICE, along with an outlook for the future experimental measurements.

Tuesday, February 25, 2020, 3:30 pm

Hosted by: Hooman Davoudiasl

Lattice gauge theory is a numerical approach to the Feynman path integral, and is the only systematically improvable approach to make theoretical predictions of hadronic properties from the underlying theory of quarks and gluons. I will present theoretical numerical calculations of hadronic properties that represent theoretical input to flavour physics, quark flavour mixing, and standard model CP violation in the Kaon, D and B mesons. These lead to constraints on CKM flavour mixing constants of the standard model, and searches for new physics.

Wednesday, February 26, 2020, 10:00 am

Bring the kids to play and the parents will have coffee, pastry and socialize! 10am-12 noon at 317 Rec Hall in the Apartment area.

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.

Wednesday, February 26, 2020, 3:00 pm

Hosted by: Hanyu Wei

The HUNTER experiment is a search for sterile neutrinos with masses in the 10-300 keV range. The neutrino missing mass will be reconstructed from 131-Cs electron capture decays occurring in a magneto-optically trapped, laser-cooled sample. Reaction-microscope spectrometers will be used to measure the vector momenta of all charged decay products with high solid angle acceptance, and LYSO scintillators read out by silicon photomultiplier arrays detect x-rays, each with sufficient resolution to reconstruct the neutrino missing mass as a peak separated from the near-zero-mass active neutrinos. The stand-alone apparatus to do this has dimensions of a few meters.

Thursday, February 27, 2020, 11:00 am

Hosted by: Mike Jensen

Friday, February 28, 2020, 11:30 am

Hosted by: African American Advancement Group

Friday, February 28, 2020, 1:30 pm

Hosted by: Mircea Cotlet

Colloidal quantum dots (QDs) are small chunk of semiconductors which, due to quantum confinement, exhibit a number of fascinating properties. Bu varying the size and/or the composition of QDs, one can easily tune their photophysical properties, like the band gap width, absorption offset or luminescence peak wavelength. This extreme tunability make QDs attractive materials for modern optical and optoelectronic applications, including solar cells, luminescent solar concentrators, light-emitting diodes, and lasers. Moreover, colloidal QDs are solution-processable, which makes them a natural choice for flexible, wearable and/or disposable electronics. In the first part of my talk, I will present how engineered QDs can be used to create a solution-processable optically-pumped laser with extremely low lasing threshold. Conventional QDs are difficult to use in lasing because of complications associated with extremely short optical-gain lifetimes limited by nonradiative Auger recombination. Here, by combining compositional grading of the QD's interior for suppressing Auger decay with post-synthetic photochemical charging for removing parasitic ground-state absorption, we reduced the lasing threshold to sub-single-exciton-per-QD limit. As a favorable departure from traditional multi-exciton–based lasing schemes, our approach should facilitate the development of solution-processable lasing devices and thereby help to extend the reach of lasing technologies into areas not accessible with traditional, epitaxially grown semiconductor materials. In the second part, I will demonstrate unusual applications of manganese (Mn) doped QDs. In these systems, the exciton generated in a QD by an absorbed photon is quickly transferred to the Mn dopant, where the collected energy can be stored for desired intervals of time (up to milliseconds) even at room temperature. Additionally, the Mn-doped QDs feature strong spin-exchange interactions bet

Friday, February 28, 2020, 2:00 pm

Hosted by: Nikhil Karthik

Wednesday, March 4, 2020, 3:30 pm

Hosted by: Viviana Cavaliere

The Higgs boson discovery at the LHC marked a historic milestone in the study of fundamental particles and their interactions. Over the last eight years, we have begun measuring its properties, which are essential to build a deep understanding of the Higgs sector of the Standard Model and to potentially uncover new phenomena. The Standard Model is far from being a complete theory of nature and many of its predictions have yet to be tested. In particular, the energy potential of the Higgs boson field, responsible for the electroweak symmetry breaking mechanism, has not yet been measured by any experiment. A measurement of the Higgs boson self-coupling at the LHC would shed light into the actual structure of the potential, whose exact shape can have deep theoretical consequences. This coupling can be accessed directly through the very challenging measurement of Higgs pair production. In this talk the experimental status of the di-Higgs boson production searches and constraints on the self-coupling at the LHC will be presented and the special role played by the decay to b-quark, the largest Higgs branching fraction, and its distinctive signature will be described.

Thursday, March 5, 2020, 11:00 am

Thursday, March 5, 2020, 3:00 pm

Hosted by: Viviana Cavaliere

Thursday, March 5, 2020, 4:00 pm

Hosted by: Mingzhao Liu

Emission of CO2, a byproduct from many industrial processes and power plants, has increased with increasing energy demand and growing population. In this talk we will first give a brief summary of CO2 conversion by H2 [1,2], followed by discussing our recent efforts in converting CO2 by light alkanes. Using a combination of kinetic studies, in situ characterization and DFT calculations, we have identified several classes of catalysts that can activate both CO2 and light alkanes [3,4]. We will then discuss how to achieve net-reduction of CO2 using mass and energy balances in thermocatalysis and electrocatalysis [5]. Finally, we will propose reducing CO2 emission by alternative pathways for N2 transformation reactions, which are currently the most CO2-emitting chemical processes [6]. [1] S. Kattel, P. Liu and J.G. Chen, "Tuning Selectivity of CO2 Hydrogenation Reactions at the Metal/Oxide Interface", J. Am. Chem. Soc. 139 (2017) 9739. [2] S. Kattel, P.J. Ramírez, J.G. Chen, J.A. Rodriguez and P. Liu, "Active Sites for CO2 Hydrogenation to Methanol on Cu/ZnO Catalysts", Science, 355 (2017) 1296. [3] B. Yan, S. Yao, S. Kattel, Q. Wu, Z. Xie, E. Gomez, P. Liu, D. Su and J.G. Chen, "Active sites for tandem reactions of CO2 reduction and ethane dehydrogenation", PNAS, 115 (2018) 8278. [4] E. Gomez, S. Kattel, B. Yan, S. Yao, P. Liu and J.G. Chen, "Combining CO2 Reduction with Propane Oxidative Dehydrogenation over Bimetallic Catalysts", Nature Commun. 9 (2018) 1398. [5] B.M. Tackett, E. Gomez and J.G. Chen, "Net reduction of CO2 via its thermocatalytic and electrocatalytic transformation reactions in standard and hybrid processes", Nature Catalysis, 2 (2019) 381. [6] J.G. Chen, R.M. Crooks, L.C. Seefeldt, et al. "Beyond Fossil Fuel-Driven Nitrogen Transformations", Science, 360 (2018) 873. Jingguang Chen is the Department Chair and

Monday, March 9, 2020, 10:00 am

Hosted by: Gerald Manbeck

Monday, March 9, 2020, 11:00 am

Hosted by: Mike Jensen

Ice clouds currently reflect ~17 W m-2 of shortwave radiation and trap ~22 W m-2 of longwave radiation on global average. However, if the distribution of cloud heights and microphysical properties changes in response to increases in greenhouse gases and aerosols, associated changes in the radiative impact of clouds could feed back on Earth's climate. Representations of ice particle density, scattering and sedimentation are needed for global and regional climate models that predict these effects. Parameterizations of other processes, such as riming, aggregation, sedimentation and evaporation, are also needed for numerical weather models that predict the destructive impact and quantitative precipitation forecasts for winter storms, hurricanes, mesoscale convective systems and other events. Further, algorithms retrieving cloud properties from ground- and satellite-based sensors require assumptions about ice crystal properties. To develop such parameterizations, accurate observations of ice particle sizes, shapes, phases and concentrations are needed. Techniques measuring these ice crystal properties are reviewed. Sources of uncertainty, related to statistical counting, variability in cloud properties for similar environmental conditions, and errors induced by the processing of data and the instruments themselves are discussed using data collected over Alaska, Australia, and the continental United States. It is shown that although there are still uncertainties in in-situ observations of small ice crystals due to potential shattering of large particles on probe tips and the limited resolution of state-of-the-art cloud particle imagers, progress on characterizing small crystals has been made. The use of instrumental and statistical uncertainties in the development of stochastic cloud parameterizations is then introduced. A specific application to the representation of mass-dimensional (m-D) relationships m=aDb is shown, where (a,b) are given as surf

Tuesday, March 10, 2020, 10:00 am

Hosted by: Christine Carter

Sign up for Costco Wholesale membership

Tuesday, March 10, 2020, 3:30 pm

Hosted by: George Redlinger

Thursday, March 12, 2020, 12:00 pm

Hosted by: Yuta Kikuchi

Thursday, March 12, 2020, 3:00 pm

Thursday, March 12, 2020, 4:00 pm

Hosted by: Abha Rajan

Thursday, March 12, 2020, 4:00 pm

Hosted by: John Hill

Experimentally realizing quantum phases of matter and controlling their properties is a central goal of the physical sciences. Novel quantum phases with controllable properties are essential for new electronic, photonic, and energy management technologies needed to address the growing societal demands for rapid and energy efficient information processing and transduction. Quantum materials offer particularly appealing opportunities for the implementation of on-demand quantum phases. This class of materials host interacting many-body electronic systems featuring an intricate interplay of topology, reduced dimensionality, and strong correlations that leads to the emergence of "quantum matter'' exhibiting macroscopically observable quantum effects over a vast range of length and energy scales. In this talk I will overview recent efforts to discover, characterize and deploy new forms of quantum matter controllable by light, gating, and nano-mechanical manipulation, effectively programming their properties. I will focus on enticing opportunities to investigate novel quantum phenomena using nascent nano-optical methods developed in my group (1,2,3) 1. S. S. Sunku, G. X. Ni, B. Y. Jiang, H. Yoo, A. Sternbach, A. S. McLeod, T. Stauber, L. Xiong, T. Taniguchi, K. Watanabe, P. Kim, M. M. Fogler, D. N. Basov "Photonic crystals for nano-light in moiré graphene superlattices" Science 362, 1153–1156 (2018). 2. G. X. Ni, A. S. McLeod, Z. Sun, L. Wang, L. Xiong, K. W. Post, S. S. Sunku, B.-Y. Jiang, J. Hone, C. R. Dean, M. M. Fogler & D. N. Basov "Fundamental limits to graphene plasmonics" Nature 557, 530 (2018). 3. A.McLeod J.Zhang, M.Q.Gu, F.Jin, G.Zhang, K.W.Post, X.G.Zhao, A.J.Millis , W.Wu, J.M.Rondinelli, R.D.Averitt, D. N. Basov "Multi-messenger nano-probes of hidden magnetism" Nature-Materials (in-press, 2020).

Friday, March 13, 2020, 2:00 pm

Hosted by: Nikhil Karthik

Wednesday, March 18, 2020, 1:30 pm

Hosted by: Layla Hormozi

TBA

Thursday, March 19, 2020, 11:00 am

Hosted by: Mike Jensen

Thursday, March 19, 2020, 3:00 pm

Hosted by: Hanyu Wei

Tuesday, March 24, 2020, 2:00 pm

Hosted by: Nikhil Karthik

Tuesday, March 24, 2020, 3:30 pm

Hosted by: George Redlinger

Detector technologies have always played a central role in particle physics experiments and enabled innovative measurements and discoveries. The development of new technologies for future experiments is increasingly complex and expensive, requiring significant human and monetary resources, as well as a long preparation period. Strong connection with industry and attention to technology transfer and societal impact have become essential elements of the development. This colloquium will discuss the main challenges in detector development, not only from the technological point of view, but also from the human resources and organizational perspectives, in particular in the context of the currently ongoing update of the European Strategy for Particle Physics

Thursday, March 26, 2020, 11:00 am

Hosted by: Alistair Rogers

Thursday, March 26, 2020, 3:00 pm

Friday, March 27, 2020, 2:00 pm

Hosted by: Nikhil Karthik

Tuesday, March 31, 2020, 2:00 pm

Hosted by: Niklas Mueller

Thursday, April 2, 2020, 11:00 am

Hosted by: Angela Burnett

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.

Thursday, April 9, 2020, 11:00 am

Hosted by: Yangang Liu

Thursday, April 9, 2020, 3:00 pm

Friday, April 10, 2020, 2:00 pm

Hosted by: Nikhil Karthik

Tuesday, April 14, 2020, 11:00 am

Hosted by: Sanjaya Senanayake

Thursday, April 16, 2020, 11:00 am

Hosted by: Ernie Lewis

Thursday, April 23, 2020, 11:00 am

Hosted by: Alistair Rogers

Thursday, April 23, 2020, 3:00 pm

Monday, April 27, 2020, 3:30 pm

Hosted by: Viviana Cavaliere

A key motivation for the next generation of particle colliders is to shed light on some of the puzzles related to our current understanding of the evolution of the universe. These comprise the quest for Dark Matter, but also the mechanism of inflation and baryogenesis. The Higgs boson discovered at the LHC could be intimately related to these questions, and therefore precision determinations of its properties at a future electron-positron collider will provide important information on a potential Dark Sector. Beyond the precision characterization of established particles like the Higgs boson, such a future electron-positron collider would offer a discovery potential for Dark Particles which is to a high degree complementary to searches at the LHC.

Thursday, April 30, 2020, 11:00 am

Hosted by: Alistair Rogers

Thursday, April 30, 2020, 5:00 pm

Hosted by: Christine Carter

Free Orientation 5-7pm on the following dates: Monday: 1/13, 2/10, 3/9, 4/20, 5/11, 6/15 Thursday: 1/23, 2/13, 3/19, 4/30, 5/21, 6/18

Thursday, May 7, 2020, 11:00 am

Hosted by: Ernie Lewis

Thursday, May 7, 2020, 3:00 pm

Tuesday, May 12, 2020, 10:00 am

Hosted by: Fernando Camino

Thursday, May 14, 2020, 11:00 am

Hosted by: Yangang Liu

Thursday, May 21, 2020, 11:00 am

Hosted by: Yangang Liu

Thursday, May 21, 2020, 3:00 pm

Friday, May 22, 2020, 2:00 pm

Hosted by: Nikhil Karthik

Thursday, May 28, 2020, 11:00 am

Hosted by: Yangang Liu

Thursday, September 17, 2020, 11:00 am

Thursday, September 24, 2020, 11:00 am

Thursday, October 1, 2020, 2:30 pm

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.

Thursday, October 8, 2020, 11:00 am

Thursday, October 15, 2020, 11:00 am

Thursday, October 22, 2020, 11:00 am

Thursday, October 29, 2020, 11:00 am

Thursday, November 5, 2020, 11:00 am

Thursday, November 12, 2020, 11:00 am

Thursday, November 19, 2020, 11:00 am