Prof. Chiara Mingarelli awarded NSF grant
Chiara Mingarelli, Assistant Professor of Physics at UConn, is the lead researcher on a $650,000 Collaborative Research Grant from the National Science Foundation, half of which is earmarked for UConn, to conduct an experiment to prove the existence of supermassive black hole binaries. This grant will combine, for the first time, traditional astronomy with gravitational […]
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A Physics Ph.D. Student’s Step-By-Step Journey to Storrs and Distant Galaxies
UConn Physics graduate student Mohammed (Mo) Akhshik works on data gathered using the Hubble Space Telescope (HST) and has led to exciting discoveries, some while he served as the science Principle Investigator of the REQUIEM HST program from which he is co-author on two publications, one in Nature and one in Nature Astronomy. Akhshik is also […]
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Professor Daniel Anglés-Alcázar research featured in ‘UConn Today’ and CBC radio interview
At the center of galaxies, like our own Milky Way, lie massive black holes surrounded by spinning gas. Some shine brightly, with a continuous supply of fuel, while others go dormant for millions of years, only to reawaken with a serendipitous influx of gas. It remains largely a mystery how gas flows across the universe […]
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Dear Friends of UConn Physics
As we approach the beginning of the 2021-22 school year, UConn is set for having classes in person again, students on campus, and our first taste of somewhat normal university life in a year and a half. Students, faculty, and staff are all required to be vaccinated, masks are required indoors, classrooms will be fully […]
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Physics alumnus Prof. Douglas Goodman and Professor Emeritus Winthrop Smith Featured in Online Peer Review Journal
Prof. Emeritus Winthrop Smith and former student Prof. Douglas Goodman (Quinnipiac University) Edit Special Issue of Open Access Journal Atoms, on Low Energy Interactions between Ions and Ultracold Atoms The Special Issue of the online journal Atoms is a collection of current peer-reviewed articles by experts in the field of ultracold collisions and reactions involving […]
[Read More]Recent Events
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Dr. Giacomo Sberveglieri, International School for Advances Studies, Trieste, Italy, "Resurgence and 1/N Expansion in Integrable Field Theories", Particle, Astrophysics, And Nuclear Physics Seminar2:00pm
12/6
Dr. Giacomo Sberveglieri, International School for Advances Studies, Trieste, Italy, "Resurgence and 1/N Expansion in Integrable Field Theories", Particle, Astrophysics, And Nuclear Physics Seminar
Monday, December 6th, 2021
02:00 PM - 03:00 PM
Other Online
Dr. Giacomo Sberveglieri,
International School for Advances Studies, Trieste, Italy
Resurgence and 1/N Expansion in Integrable Field Theories
In theories with renormalons the perturbative series is factorially divergent even after restricting to a given order in 1/N, making the 1/N expansion a natural testing ground for the theory of resurgence. We studied in detail the interplay between resurgent properties and the 1/N expansion in various integrable field theories with renormalons, namely the non-linear sigma model, the principal chiral field and the Gross-Neveu models. We focused on the free energy in the presence of a chemical potential coupled to a conserved charge, which can be computed exactly with the thermodynamic Bethe ansatz (TBA). In this talk, after an introduction on the nature of perturbative series and having set the key ingredients and tools of our study, I'll present and discuss the results: they turned out to be different in the three models. While in some examples, the terms in the 1/N expansion can be fully decoded in terms of a resurgent trans-series in the coupling constant, in others each term in the 1/N expansion includes non-perturbative corrections which can not be predicted by a resurgent analysis of the corresponding perturbative series. Notably, in the principal chiral field we found a new, explicit solution for the large N free energy which can be written as the median resummation of a trans-series with infinitely many, analytically computable IR renormalon corrections.
Meeting URL: https://us02web.zoom.us/j/82042659112?pwd=VmtHMWcxcEdZMmJoV0VlVmR4WEg3UT09 -
Postponed for later date:, Dr. Tonica Valla, Brookhaven National Laboratory, Cancelled: UConn Physics Colloquium3:30pm
12/3
Postponed for later date:, Dr. Tonica Valla, Brookhaven National Laboratory, Cancelled: UConn Physics Colloquium
Friday, December 3rd, 2021
03:30 PM - 04:30 PM
Storrs Campus Gant North 20 (formerly IMS-20)
Postponed for later date:
Dr. Tonica Valla, Brookhaven National Laboratory
ARPES View of High Tc Superconductivity: Endgame and New Beginning
Cuprate high Tc superconductors (HTSC) may hold the promise of lossless transport of electrical power, a net positive fusion power generation, and quantum computing devices, but after more than 35 years of discovery and intense research, the mechanism of HTSC in cuprates remains unresolved. Moreover, most of the current studies are focused on phenomena in the underdoped materials that are largely unrelated to the most important unanswered question: what is the mechanism of superconductivity in cuprates? Here, I will present the capabilities of angle-resolved photoemission spectroscopy (ARPES) and show that this technique is perfectly suited to provide a smoking gun evidence for the pairing mechanism in cuprates, just as the planar tunneling was for conventional superconductors. I will present the ARPES studies of a prototypical cuprate, Bi2Sr2CaCu2O8+d, in a wide range of doping, covering not only the superconducting dome, but also its endpoint on the overdoped side and the non-superconducting metallic phase. In the strongly overdoped regime, where superconductivity is the only remaining order, free of complications that usually pollute the underdoped regime, we detect anomaly in the state's dispersion that monotonically weakens with increasing doping and completely disappears precisely where superconductivity disappears - a tell-tale sign of its involvement in the pairing interaction. Our study indicates that the resolution of high Tc problem might finally be in sight by providing a direct connection of the detected anomaly with superconductivity.
I will also discuss the problems and potential solutions in using the cuprates as a platform for topological superconductivity.
Live streame: https://www.kaltura.com/index.php/extwidget/preview/partner_id/2090521/uiconf_id/37067881/entry_id/1_6kfe72n4/embed/iframe -
Undergraduate student N. Zimmerman and Prof. M. Gai, Department of Physics, University of Connecticut, "GEANT4, a simulation toolkit", Graduate Student Seminar12:15pm
12/3
Undergraduate student N. Zimmerman and Prof. M. Gai, Department of Physics, University of Connecticut, "GEANT4, a simulation toolkit", Graduate Student Seminar
Friday, December 3rd, 2021
12:15 PM - 01:15 PM
Storrs Campus GS-119
Undergraduate student N. Zimmerman and Prof. M. Gai, Department of Physics, University of Connecticut
GEANT4, a simulation toolkit
GEANT4, is an elementary toolkit for the simulation of the passage of particles through matter [1] with applications in high energy, nuclear and accelerator physics, as well as studies in medical and space science.
Data stored "on tape" collected at Duke University in 2012, using our optical readout time projection chamber (O-TPC) detector, was analyzed by our research group. It allowed us to address the central problem of Stellar Evolution: the C/O ratio at the end of helium burning. This research was published [2]. A more palatable review of our research intended for the non-experts [3]; for example, a Type II supernova progenitor star with C/O 1 leaves behind a neutron star.
[1] J. Allison et al., Nuclear Instruments and Methods in Physics Research A 835 (2016) 186-225,
https://www.sciencedirect.com/science/article/pii/S0168900216306957
[2] Robin Smith, Moshe Gai, Sarah R. Stern, Deran K. Schweitzer and Mohammad W. Ahmed, Nature Communications, 12(2021)5920.
https://www.nature.com/articles/s41467-021-26179-x
[3] Moshe Gai and Robin Smith, Shinning a Light on Nuclear Astrophysics, The Innovation Platform,
https://www.innovationnewsnetwork.com/shining-light-nuclear-astrophysics/15139/ -
Dr. Sarah Wellons, Northwestern University, "Simulating the Growth and Quenching of Massive Galaxies from the Early Universe to Today ", Astronomy Seminar2:00pm
12/1
Dr. Sarah Wellons, Northwestern University, "Simulating the Growth and Quenching of Massive Galaxies from the Early Universe to Today ", Astronomy Seminar
Wednesday, December 1st, 2021
02:00 PM - 03:00 PM
Storrs Campus GS-119
Dr. Sarah Wellons,
Northwestern University
Simulating the Growth and Quenching of Massive Galaxies from the Early Universe to Today
Great observational progress over the past decade has revealed how galaxies have changed over cosmic time. One surprising revelation was the existence of massive, "red and dead" galaxies which had already reached masses exceeding that of the Milky Way and ceased forming stars (or "quenched") only a few gigayears after the Big Bang. These objects present a challenge to theorists: how can they form and quench so quickly? I will discuss some recent simulation studies of these objects, and use them as a focus to examine one of the major outstanding questions in galaxy formation theory: how do supermassive black holes (SMBHs) coevolve with their host galaxies, and [how] are they responsible for galaxy quenching? I will begin with an overview of the known observational scaling relations, the physics of galaxy formation, and how that physics is implemented in simulations, and show a few examples of how we can learn about the formation of massive galaxies using different simulation approaches. A major uncertain element in simulating galaxy formation is the implementation of SMBH physics, since it occurs at scales well below the achievable spatial resolution. Because the fundamental physics is unresolved, simulators have significant flexibility in choosing how to implement it at the galaxy scale. In the latter portion of my talk, I will present results from a large suite of zoom-in simulations exploring a variety of implementations and parameterizations for modeling SMBH physics to address the question: what are the common physical properties of SMBH models that produce realistic quenching behavior at different halo mass scales?
Meeting URL: https://uconn-cmr.webex.com/meet/daa19013 -
Prof. Hugh Churchill, University of Arkansas, "Quantum Devices with 2D Insulators and Semiconductors", Condensed Matter Physics Seminar1:00pm
12/1
Prof. Hugh Churchill, University of Arkansas, "Quantum Devices with 2D Insulators and Semiconductors", Condensed Matter Physics Seminar
Wednesday, December 1st, 2021
01:00 PM - 02:00 PM
Storrs Campus GW-119
Prof. Hugh Churchill, University of Arkansas
Quantum Devices with 2D Insulators and Semiconductors
I will describe two applications of 2D layered materials for quantum devices. First, I will discuss gate-tunable Josephson junction field-effect transistors (JJ-FETs) based on Al/InAs in which the gate dielectric is thin hBN. Comparing devices with hBN and AlOx dielectrics, we observe that the product of normal resistance and critical current, IcRn, is comparable for both types of devices. However, Rn is strikingly higher for the hBN-based devices indicating that the surface is doped less compared to AlOx gate dielectric. These results demonstrate that hBN provides a superior gate dielectric compared to AlOx for JJ-FET devices with applications in superconducting logic and quantum information technologies such as gatemon qubits and topological superconductivity. Second, I will discuss our work to fabricate and characterize gate-defined, accumulation mode quantum dots using monolayer and bilayer WSe2. Temperature dependence of conductance in the Coulomb-blockade regime is consistent with transport through a single level, and excited-state transport through the dots is observed at temperatures up to 10 K. These devices provide a platform to evaluate valley-spin states in monolayer and bilayer WSe2 for application as qubits. I will also briefly advertise the recently established MonArk NSF Quantum Foundry which seeks to accelerate the fabrication and characterization of 2D quantum materials to serve a broad community of users. -
Prof. Martha Constantinou, Temple University, "Beyond Leading-Twist Proton Structure from Lattice QCD: The Twist-3 Case", Particle, Astrophysics, And Nuclear Physics Seminar2:00pm
11/29
Prof. Martha Constantinou, Temple University, "Beyond Leading-Twist Proton Structure from Lattice QCD: The Twist-3 Case", Particle, Astrophysics, And Nuclear Physics Seminar
Monday, November 29th, 2021
02:00 PM - 03:00 PM
Storrs Campus GS-119
Prof. Martha Constantinou, Temple University
Beyond Leading-Twist Proton Structure from Lattice QCD: The Twist-3 Case
Parton distribution functions (PDFs) have a central role in understanding the hadron structure and have been calculated in lattice QCD mainly via their Mellin moments. The landscape of roton structure has changed with new methods to access the x dependence of distribution functions. In this talk, we will present results using the approach of quasi-distributions, which relates lattice data to light-cone distributions. The method relies on matrix elements of fast-moving hadrons coupled to non-local operators. These are matched to the light-cone PDFs using Large Momentum Effective Theory (LaMET). I will present the twist-2 unpolarized, helicity and transversity GPDs, and also also demonstrate the feasibility of the approach for twist-3 PDFs and GPDD explored in lattice QCD for the first time. The calculation is performed on one ensemble of two degenerate light, a strange and a charm quark (Nf=2+1+1) of maximally twisted mass fermions with a clover term, reproducing a pion mass of 260 MeV. -
Dr. Gökçe Basar, University of North Carolina, "The search for the QCD critical point ", UConn Physics Colloquium3:30pm
11/19
Dr. Gökçe Basar, University of North Carolina, "The search for the QCD critical point ", UConn Physics Colloquium
Friday, November 19th, 2021
03:30 PM - 04:30 PM
Other Online
Dr. Gökçe Basar, University of North Carolina
The search for the QCD critical point
The strong force binds the building blocks of protons and neutrons, quarks and gluons, together and creates most of the observed mass in the universe. At a few trillion degrees, these bonds break, and matter transitions into a new phase called Quark Gluon Plasma (QGP). QGP once filled the universe when it was microseconds old, and today is recreated in the heavy ion collision experiments with the goal of understanding how matter behaves at these extreme temperatures and densities. What do we know about the phases of matter at these extreme environments? What is the nature of the phase transition between ordinary matter and QGP? Is there a critical point in the phase diagram and if there is how can we locate it? I will give an overview of the status of the theoretical and experimental efforts to answer these questions as well as the future challenges.
Meeting URL: https://unc.zoom.us/j/93578592137?pwd=WUhpWjk3SjBIVEF0d0pWZ09GT2p3dz09 -
Prof. ChandraSekhar Roychoudhuri, Department of Physics, University of Connecticut, "Seeking Reality of Nature Is the cosmic space a vacuum, or a physical medium?", Graduate Student Seminar12:15pm
11/19
Prof. ChandraSekhar Roychoudhuri, Department of Physics, University of Connecticut, "Seeking Reality of Nature Is the cosmic space a vacuum, or a physical medium?", Graduate Student Seminar
Friday, November 19th, 2021
12:15 PM - 01:15 PM
Storrs Campus GS-119
Prof. ChandraSekhar Roychoudhuri, Department of Physics, University of Connecticut
Seeking Reality of Nature
Is the cosmic space a vacuum, or a physical medium?
Over the last two decades, a good number of books have been written by many serious physicists that current physics, while steadily "chugging along" (as publications and findings indicate), has failed to develop any major new thinking
since the fundamental papers in Quantum Mechanics were published. In this talk, I will present the limitations of the
prevailing Evidence Based Science (EBS) and show that the incorporation of interaction process visualization as a
standard engineering thinking tool, will give us a lot more insights into the existing working theories while revealing the limitations that need to be addressed. Resolving these limitations will open up many new and better understanding of nature, while getting rid of most of the mystical interpretations of the current working theories.
[1] C. Roychoudhuri, "Cosmic Ether, Possessing Electric-Tension and Magnetic-Resistance, Is the Unified Field for Physics", Journal of Modern Physics, 2021, 12, 671-699