sPHENIX discussion of physics

["Perepelitsa, Dennis" <dvp AT bnl.gov>]

Hi sPHENIX colleagues,

You may be interested in this Nuclear Physics Seminar later today at 11am BNL time. The ALICE Large-R result was one of the more discussed (and speculated on) jet results at Quark Matter ’22.

Dennis

Begin forwarded message:

From: <elamar AT bnl.gov>

Subject: Today's Seminars

Date: May 12, 2022 at 5:03:03 AM PDT

To: <physics-seminars-l AT lists.bnl.gov>

Reply-To: <elamar AT bnl.gov>, <leesa AT bnl.gov>

Nuclear Physics Seminar
"Measurement of the R-dependence of inclusive jet suppression in Pb–Pb collisions with ALICE"
Presented by Hannah Bossi, Yale University

Thursday, May 12, 2022, 11:00 am — Hybrid:Bldg. 510, Small Seminar Room

Abstract: Jets in relativistic heavy-ion collisions interact with the quark-gluon plasma (QGP), leading to
effects such as a suppression of jet yields and modification of internal jet structure that can be used
to constrain properties of the QGP. The dependence of jet suppression on the resolution parameter
(R) and jet pT is a useful observable to disentangle competing energy loss mechanisms with a high
discriminating power when compared to models. Due to the presence of the large underlying event
in heavy-ion collisions, measurements at large R and low pT are limited by the pT resolution using
traditional techniques. A new method using machine learning techniques is used to correct the large
background in heavy-ion collisions and extend the measurement of inclusive jet yields to lower pT
than previously achieved in heavy-ion collisions at the LHC. This talk will present the inclusive
jet nuclear modification factors in Pb–Pb collisions in various centrality classes at √sNN = 5.02
TeV recorded with the ALICE detector for resolution parameters up to R = 0.6 for jet transverse
momenta down to 40 GeV/c. These results suggest that jets reconstructed with larger resolution
parameters are more suppressed. Comparisons with jet quenching models will also be shown.

Hosted by: Tim Rinn

Join Videoconference: https://bnl.zoomgov.com/j/1618659309?pwd=Unc4QTY4QUlBUXoyY1lEeGRMSDh2Zz09
More Information: https://indico.bnl.gov/event/15398/


Condensed-Matter Physics & Materials Science Seminar
"Possible high temperature superconductivity in VSe2"
Presented by Turgut Yilmaz, NSLS-II

Thursday, May 12, 2022, 11:00 am — Bldg. 734, Virtual

Superconductivity in transition metal dichalcogenides is highly demanded due to being a host material family for rich physical phenomena ranging from charge density wave order to topological states. However, superconducting transition metal dichalcogenides have a transition temperature far below 10 K hindering future studies and applications. Here, I will present a detailed angle-resolved photoemission study conducted from VSe2 grown in different forms and under various conditions and show that superconductivity can be induced in VSe2 by the proper selection of substrate and growth parameters. Evidence for the superconducting state comes from the simultaneous detection of spectral kink, quasiparticle peak, Fermi gap, and their evolution with the temperature. The photoemission experiment also provides evidence for a formation of a pseudogap state at high temperatures, characterized by the progressive quenching of the quasiparticle peak feature coexisting with a persistent gap at the Fermi level, a behavior reminiscent of high-Tc superconductors. Although Tc cannot be accurately determined from photoemission data, observations based on the survival temperature of the quasiparticle peak suggest that Tc could be as high as 100 K and substantially higher than previous reports for any transition metal dichalcogenides.

Contributors: Elio Vescovo (NSLS-II), Jerzy T. Sadowski (CFN), Boris Sinkovic (UCONN)

Hosted by: Mark Dean

Join Videoconference: https://bnl.zoomgov.com/j/1605824360?pwd=UW1PWDJBdHo3dkVRRWpTVWo5Ykx2QT09&from=addon
More Information:


RBRC seminar
"Stochastic normalizing flows for lattice field theory"
Presented by Alessandro Nada

Thursday, May 12, 2022, 12:30 pm — Videoconference / Virtual Event (see link below)

Abstract: A class of deep generative models called Normalizing Flows has been recently proposed as a promising alternative to conventional Markov Chain Monte Carlo simulations to sample lattice field theory configurations: these models provide a unique approach to potentially avoid the large autocorrelations that characterize Monte Carlo simulations close to the continuum limit. In this talk we explore the novel concept of Stochastic Normalizing Flows (SNFs), in which neural-network layers are combined with traditional Monte Carlo updates: in particular, we show how SNFs share the same theoretical framework of out-of-equilibrium simulations based on Jarzynski's equality. The latter is a well-known result in non-equilibrium statistical mechanics that has already been successfully used in computations of free-energy differences in lattice gauge theories. We discuss how the connection between Normalizing Flows and Jarzynski's equality can be exploited to optimize the efficiency of this extended class of generative models and we present some numerical results in an example of application.

Hosted by: Vladi Skokov

Join Videoconference: https://bnl.zoomgov.com/j/1606067399?pwd=am02b0xIUXZ6TDR3d1dWL05TTDdaUT09
More Information: https://indico.bnl.gov/event/14896/


CFNS Seminar
"Understanding spin polarization of Lambda hyperons through spin hydrodynamics"
Presented by Rajeev Singh, Institute of Nuclear Physics Polish Academy of Sciences

Thursday, May 12, 2022, 4:00 pm — Videoconference / Virtual Event (see link below)

Abstract: Since the first positive measurement of the Λ-hyperon global spin polarization in heavy-ion collisions by STAR in 2017, the understanding of the nature of this phenomenon is one of the most intriguing challenges for the scientific community. As relativistic fluid dynamics celebrates multiple successes in describing collective dynamics of the QCD matter in such reactions, the natural question arises whether the spin dynamics can also be modelled in such a framework. In this talk, the motivation for and recent outcomes of the experimental hunt for the macroscopic footprints of quantum spin in the relativistic heavy-ion collisions will be presented and the theoretical challenges connected with formulating its collective description will be discussed. In addition, I will also present the recent results of the space-time evolution of spin polarization within the framework of hydrodynamics with spin based on the de Groot - van Leeuwen - van Weert forms of energy-momentum and spin tensors in the non-boost invariant background.

Related papers: https://arxiv.org/abs/2112.01856, https://arxiv.org/abs/2103.01013, https://arxiv.org/abs/2103.02592, https://arxiv.org/abs/2011.14907, https://arxiv.org/abs/1901.09655.

Hosted by: Barak Schmookler

Join Videoconference: https://stonybrook.zoom.us/j/94818312295?pwd=ek1kRjBWV3E1VkgyRTZnQzg0d0tWQT09
More Information:


Thank you,
Erica Lamar
Brookhaven National Laboratory
Physics Department
Sr. Administrative Assistant to the Chair's Office
Building 510A
Upton, NY 11973-5000
(631) 344-2585
elamar AT bnl.gov<mailto:elamar AT bnl.gov>
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Dennis V. Perepelitsa

Assistant Professor, Physics Department

University of Colorado Boulder