The topics of this online seminar series cover broad aspects of hot and dense QCD matter, with an emphasis on physics related to RHIC beam energy scan (BES) program.
The fifth season of the series will take place
Before Nov. 6th: 9pm (Beijing)=10:00pm (Tokyo)=6:30pm (New Delhi)=3:00pm (Frankfurt) =6:00 am (San Francisco)=9:00 am (New York)
After Nov. 6th: 10pm (Beijing)=11:00pm (Tokyo)=7:30pm (New Delhi)=4:00pm (Frankfurt) =6:00 am (San Francisco)=9:00 am (New York)
every Tuesday between Sep. 6th and Dec. 13th (excluding thanksgiving), 2022.
1. Sep. 6
Unnuclear Physics: Conformal Symmetry in Nuclear Reactions
Dam Son (U. Chicago)
Abstract: Conformal symmetry plays an important role in quantum field theory and statistical physics. A nonrelativistic version of the conformal symmetry, also called Schrödinger symmetry, is approximately realized in various physical systems, including neutrons in nuclear physics and ultracold atoms. After going through some basic facts about nonrelativistic conformal field theory, we describe an application to nuclear reactions with several neutrons in the final state.
Chair: Thomas Schäfer (NCSU)
2. Sep. 13
Embedding a Critical Point in a Background Equation of State for QCD
Joseph Kapusta (UMN)
Abstract: Lattice QCD simulations have shown unequivocally that the transition from hadrons to quarks and gluons is a crossover when the baryon chemical potential is zero or small. Many model calculations predict the existence of a critical point at a value of the chemical potential where current lattice simulations are unreliable. We show how to embed a critical point in a smooth background equation of state in two very different ways so as to yield the critical exponents and critical amplitude ratios expected of a transition in the same universality class as the liquid--gas phase transition and the 3D Ising model. The resulting equations of state have parameters which may be inferred by hydrodynamic modeling of heavy ion collisions in the Beam Energy Scan II at the Relativistic Heavy Ion Collider or in experiments at other accelerators.
Chair: Rob Pisarski (BNL)
3. Sep. 20
Heavy Ion Collisions: What Next?
Krishna Rajagopal (MIT)
Abstract: The organizers have asked me to provide an introduction to heavy ion physics. Since in the U.S. we are in the midst of developing the next long range plan for nuclear physics, I thought I would begin by introducing heavy ion physics in the way that we did around the time of the previous long range plan, circa 2015. By looking at this introduction from today’s perspective, we can see how robust the big picture we had at that time was and highlight recent progress. In the second half of the talk I will look ahead.
Chair: Berndt Müller (Duke)
4. Sep. 27
Exploration of Matter in Extreme conditions with Machine Learning
Kai Zhou (FIAS)
Abstract: In this talk I will demonstrate how we can use machine learning based computational paradigm to help our exploration of QCD matter in extreme conditions. The focus is about properties of hot and dense nuclear matter related studies. Around it, experimentally the relativistic nuclear collision are performed to realize the extreme conditions for studying it while theoretically the first-principle lattice field theory constructs the main path to investigate the equilibrium thermodynamics of the matter. Meanwhile, the astronomical observations on Neutron Star also provide constraints on the equation of state of the dense nuclear matter. Machine Learning within the broadly Artificial Intelligence (AI) brand is a rapidly developing field that has been proven to be powerful in recognizing patterns from complex data, and powerful as well in representing relationships/mappings of systems. This modern computation technologies has become increasingly prominent in all sectors of our everyday life, and also into frontiers of scientific research especially in computational related studies. Specifically, in this talk I will introduce the potential of machine learning for research about hot and dense nuclear matter, ranging from identifying essential physics from nuclear collision experiment, to assisting the lattice QCD data analysis, and to efficiently exploiting astronomical observations in inferring the Neutron Star equation of state.
Chair: Huichao Song (PKU)
5. Oct. 4
QCD Phase Diagram and the Equation of State of Strong-Interaction Matter
Frithjof Karsch (U. Bielefeld)
Abstract: Lattice QCD calculations at non-zero temperature and with non-vanishing chemical potentials provide a powerful framework for the analysis of the phase structure of strong-interacting matter. Such calculations allow the determination of the crossover transition region at QCD with physical quark masses as well as the determination of the true chiral phase transition in the limit of vanishing light quark masses.
In this talk we focus on applications of the Taylor expansion approach to the analysis of QCD at non-vanishing values of the chemical potentials. We present results on the determination of the pseudo-critical and chiral phase transition temperatures at vanishing and non-vanishing values of the chemical potentials. We furthermore present a new, high statistics determination of the QCD equation of state. We point out their importance for constraining the location of a possible critical end point in the QCD phase diagram. If time permits, we will also present results on higher order cumulants at non-vanishing baryon chemical potential in strangeness neutral matter and compare them with experimental data on net proton-number fluctuations obtained by STAR and ALICE.
Chair: Claudia Rattic (U. Houston)
6. Oct. 11
Electromagnetic radiation in heavy-ion collisions; what it tells us about non-equilibrium physics
Charles Gale (McGill):
Abstract: In this talk, I will concentrate on calculations and measurements of real photons, and review and highlight what is known about their sources. I will also discuss several aspects where photon measurements inform our knowledge of the non-equilibrium features of relativistic heavy-ion collisions.
Chair: Rapp Ralf (TAMU)
7. Oct. 18
Relativistic Navier-Stokes equations
Pavel Kovtun (U. Victoria)
Chair: Michal Heller (Gent U)
8. Oct. 25
Light nuclei production in HIC
Elena Bratkovskaya (GSI)
Abstract: The understanding of the mechanisms for the production of weakly bound clusters in heavy-ion reactions at midrapidity is presently one of the challenging problems which is also known as the " ice in a fire" puzzle. We study cluster and hypernuclei production employing the Parton-Hadron-Quantum-Molecular-Dynamics (PHQMD) approach, a microscopic n-body transport model based on the QMD propagation of the baryonic degrees of freedom with density dependent two-body potential interactions. In PHQMD the cluster formation occurs dynamically, caused by the potential interactions (and recognized by the Minimum Spanning Tree (MST) or the Simulated Annealing Cluster Algorithm (SACA)). Additionally deuterons can be produced by kinetic reactions via pion or nucleon catalysis. We study the time evolution of formed clusters and the origin of their production, which helps to understand how such weakly bound objects are formed and survive in the rather dense and hot environment created in heavy-ion collisions.
Chair: Xiaofeng Luo (CCNU)
9. Nov. 1
Dense Matter and Dark Matter in Compact Objects: Status and Prospects
Sanjay Reddy (INT)
Abstract: In the past decade, multi-messenger observations of phenomena involving neutron stars (NSs) have provided valuable insights into dense matter. I will review theoretical efforts to interpret these observations and discuss implications for the sound speed in dense QCD and the cooling and transport properties of dense neutron star matter. Neutron stars can also serve as laboratories to study sub-GeV dark matter, and I will provide a few examples to make this case.
During the next decade, as gravitational wave observatories get upgraded, compact object mergers are poised to play a key role in multi-messenger astrophysics. I highlight some of the science that it will enable. I will also discuss how next-generation gravitational wave detectors (Cosmic Explorers and Einstein Telescope) can impact nuclear and particle physics and speculate on a precision era in compact object studies.
Chair: Kenji Fukushima (U. Tokyo)
10. Nov. 8
Nuclear structure for high-energy nuclear collisions
Giuliano Giacalone (Heidelberg)
Abstract: Over the past two years the connection between low-energy nuclear structure and high-energy heavy-ion collisions has been the focus of much discussion and activity, both in theory and in experiment. This is due to two facts. First, the great success of the hydrodynamic model of the quark-gluon plasma enables us today to carefully scrutinize how the precise input from nuclear structure physics affects the final outcome of high-energy nuclear collisions. Second, the availability of experimental data from multiple collision systems has permitted us to identify unambiguous signals of structural properties of nuclei in the experimental measurements. After recalling the basics of high-energy nuclear scattering, I review the status of the observed manifestations of so-called nuclear deformations, reflecting collective spatial correlations of nucleons in the nuclear wave functions, at high-energy colliders. I emphasize that the expectations of low-energy nuclear physics appear to be consistently fulfilled by the observations at high energy, bringing confidence to our understanding of the collision processes. I discuss the prospects for theoretical and experimental studies aimed at exploiting the structure of nuclei via light- and heavy-ion collisions to further improve our understanding of nuclear phenomena across energy scales.
Chair: Bjoern Schenke (BNL)
11. Nov. 15
Hadron Interactions from Lattice QCD - Theory meets Experiments
Tetsuo Hatsuda (RIKEN)
Abstract: Recent progress in lattice QCD simulations close to the physical pion mass opens the door for quantitative studies of poorly understood hadron-hadron interactions with strangeness at low energies. It also allows comparison with femtoscopic studies in pp, pA, and AA collisions at RHIC and LHC. After an overview of the basic theoretical concepts of the HAL QCD method for extracting hadronic interactions from lattice QCD, an interplay between theoretical and experimental studies will be presented, with Lambda-Lambda, N-Xi, N-Omega, Omega-Omega, and N-phi interactions as examples. The ongoing program of physical point lattice QCD simulations using RIKEN's 440 PFlops supercomputer FUGAKI will also be mentioned.
Chair: Laura Fabbietti (TUM)
12. Nov. 29
Some Recent Progress in Quantum Simulations for Nuclear Physics
Martin Savage (INT)
Abstract: I will tell you about recent progress that we have made in performing quantum simulations of a few interesting systems of relevance to nuclear physics. These include the dynamics and beta-decays in 1+1D QCD, entanglement evolution in systems of dense neutrinos, the O(3) non-linear sigma model, and optimizing effective model spaces in the Lipkin-Meshkov-Glick model.
Chair: Dimitri Kharzeev (Stony Brook & BNL)
13. Dec. 6
Hot QCD with sPHENIX at RHIC
Gunther Roland (MIT)
Over the last decades heavy-ion experiments at RHIC and LHC have demonstrated a range of novel QCD phenomena that emerge under conditions of extreme temperature, related to the production of high density matter in form of a Quark-Gluon Plasma (QGP). The observed properties of QGP, such as near-perfect fluidity and extreme opacity, make it unique among all known forms of matter. New efforts, sPHENIX at RHIC and the upgraded LHC experiments, will begin collecting high precision new data in the next year. These data will allow us to investigate the microscopic origins of the fascinating QGP properties. Of particular importance will be the complementarity of RHIC and LHC experiments, covering very different collision energy regimes, and thus allowing us to investigate the temperature dependence of QGP properties. In this talk I will recall some of the main pillars of our current understanding of QGP, and discuss expectations for future new insights from the sPHENIX experiment currently finishing construction.
Chair: Yen-Jie Lee (MIT)
14. Dec. 13
The ELectron Ion Collider: A Unique New Microscope for Matter
John Lajoie (Iowa State U)
The visible world around us is made up of atoms, with protons and neutrons forming the nuclei at their core. Together, protons and neutrons make up most of the mass of everything we see in the universe today, from massive galaxies to individual people. Protons and neutrons themselves are complicated many-body quantum states whose prpoerties are determined by the quarks and gluons that they are comprised of. The quest to understand in detail the structure of protons, neutrons, and nuclei is nothing less that an attempt to answer the questions "What are we made of? What is matter?" The Electron Ion Collider (EIC), to be built by JLab and BNL, will be a unique new machine to collide polarized electrons off polarized protons and light nuclei, providing the capability to study multi-dimensional tomographic images of protons and nuclei, and collective effects of gluons in nuclei. In this colloquium I will motivate the physics program at the EIC and the unique new machine and detectors that will be required to answer these fundamental questions.
Chair: Abhay Deshpande (Stony Brook)
The interested participants are kindly requested to register through "registration" on the left side of the indico page. By attending this event you agree that the seminar and discussion being recorded and posted on the seminar web site.
Heinz, Ulrich (OSU) email@example.com
Luo, Xiaofeng (CCNU) firstname.lastname@example.org
Ratti, Claudia (UH) email@example.com
Song, Huichao (PKU) firstname.lastname@example.org
Xu, Nu (LBNL) email@example.com
Yin, Yi (IMP) firstname.lastname@example.org
Code of Conduct :
The organizers are committed to making this seminar series productive and enjoyable for everyone. Creating a supportive professional environment where open and frank discussion of ideas can take place, where everyone is treated with courtesy and respect, and in which diversity and inclusion are valued is the responsibility of all the participants. We will not tolerate harassment of attendees or others involved in the conference in any form. By joining the Zoom call, you agree to follow these guidelines:
1) Behave professionally in personal interactions. Harassment and sexist, racist, or exclusionary comments or jokes are not appropriate. Harassment includes sustained disruption of talks or scientific discussions, deliberate intimidation, stalking, offensive comments related to gender identity, sexual orientation, disability, physical appearance, body size, race, nationality, or the religion or non-religion of participants.
2) Be kind to others. Do not insult or put down the speaker or the other attendees. Scientific discussion and criticism is vital and should be conducted in this spirit.
3) All communication should be appropriate for a professional audience including people of many different backgrounds.
Should a participant be asked to stop any inappropriate behavior, they are expected to comply immediately. In serious cases, they may be muted or asked to leave the meeting at the sole discretion of the organizers.