المؤلفون: Grefa, Joaquin^1,2 vgrefaju@central.uh.edu, Hippert, Mauricio³, Elayavalli, Raghav Kunnawalkam⁴, Noronha-Hostler, Jacquelyn², Portillo, Israel¹, Ratti, Claudia¹, Rougemont, Romulo⁵

المصدر: EPJ Web of Conferences. 6/26/2024, Vol. 296, p1-4. 4p.

مصطلحات موضوعية: *DILATON, *QUANTUM chromodynamics, *LATTICE quantum chromodynamics, *THERMODYNAMICS, *COLLISIONS (Nuclear physics), *NUCLEAR physics

مستخلص: We employ an Einstein-Maxwell-dilaton model, based on the gauge/gravity correspondence, to obtain the thermodynamics and transport properties for the hot and dense quark-gluon plasma. The model, which is constrained to reproduce lattice QCD thermodynamics at zero density, predicts a critical point and a first order line at finite temperature and density, is used to quantify jet energy loss through simulations of high-energy collision events. [ABSTRACT FROM AUTHOR]

المؤلفون: Ding, Heng-Tong¹ hengtong.ding@ccnu.edu.cn, Huang, Wei-Ping¹ huangweiping@mails.ccnu.edu.cn, Mukherjee, Swagato² swagato@bnl.gov, Petreczky, Peter² petreczk@bnl.gov

المصدر: EPJ Web of Conferences. 6/26/2024, Vol. 296, p1-4. 4p.

مصطلحات موضوعية: *CHIRALITY of nuclear particles, *QUANTUM chromodynamics, *PAIRING correlations (Nuclear physics), *LATTICE quantum chromodynamics, *QUARK matter, *NUCLEAR physics

مستخلص: We reveal that the criticality of the chiral phase transition in QCD at the macroscale arises from the microscopic energy levels of its fundamental constituents, the quarks. We establish a novel relation between cumulants of the chiral order parameter (i.e., chiral condensate) and correlations among the energy levels of quarks (i.e., eigenspectra of the massless Dirac operator), which naturally leads to a generalization of the Banks-Casher relation. Based on this novel relation and through (2+1)-flavor lattice QCD calculations using the HISQ action with varying light quark masses in the vicinity of the chiral phase transition, we demonstrate that the correlations among the infrared part of the Dirac eigenspectra exhibit same universal scaling behaviors as expected of the cumulants of the chiral condensate. We find that these universal scaling behaviors extend up to the physical values of the up and down quark masses. [ABSTRACT FROM AUTHOR]

المؤلفون: Parotto, Paolo^1,2 paolo.parotto@unito.it, Borsányi, Szabolcs³, Fodor, Zoltan^2,3,4,5,6, Guenther, Jana N.³, Kara, Ruben³, Pásztor, Attila^4,7, Ratti, Claudia⁸, Szabó, Kalman K.^3,5

المصدر: EPJ Web of Conferences. 6/26/2024, Vol. 296, p1-4. 4p.

مصطلحات موضوعية: *QUANTUM chromodynamics, *EQUATIONS of state, *LATTICE quantum chromodynamics, *BARYONS, *NUCLEAR physics

مستخلص: The equation of state of Quantum Chromodynamics has been in recent years the focus of intense effort from first principle methods, mostly lattice simulations, with particular interest to the finite baryon density regime. Because of the sign problem, various extrapolation methods have been used to reconstruct bulk properties of the theory up to as far as μB=T ≃ 3:5. However, said efforts rely on the equation of state at vanishing baryon density as an integration constant, which up to μB=T ≃ 2 - 2:5 proves to be the dominant source of uncertainty at the level of precision currently available. In this contribution we present the update of our equation of state at zero net baryon density from 2014, performing a continuum limit from lattices with Nτ = 8; 10; 12; 16. We show how the improved precision is translated in a lower uncertainty on the extrapolated equation of state at finite chemical potential. [ABSTRACT FROM AUTHOR]

المؤلفون: Borsányi, Szabolcs¹ borsanyi@uni-wuppertal.de, Fodor, Zoltán^1,2,3,4,5, Guenther, Jana N.¹, Katz, Sändor D.³, Parotto, Paolo^2,6, Pásztor, Attila³, Pesznyák, Dávid³, Szabó, Kálmán K.^1,4, Wong, Chik Him¹

المصدر: EPJ Web of Conferences. 6/26/2024, Vol. 296, p1-4. 4p.

مصطلحات موضوعية: *LATTICE quantum chromodynamics, *BARYONS, *DISCRETIZATION methods, *QUANTUM chromodynamics, *CHIRALITY of nuclear particles

مستخلص: We calculate the grand canonical fluctuations of the net baryon number and net strangeness in the region of chiral crossover from lattice QCD. We continuum extrapolate the results in a finite volume using the new 4HEX discretization scheme up to χ6B and also for χ8B at a single temperature. Our results contradict recent estimates at a finite lattice spacing. See Ref. [1] for the full version of this work. [ABSTRACT FROM AUTHOR]

المؤلفون: Başar, Gökçe¹ gbasar@unc.edu

المصدر: EPJ Web of Conferences. 6/26/2024, Vol. 296, p1-4. 4p.

مصطلحات موضوعية: *QUANTUM chromodynamics, *EQUATIONS of state, *BARYONS, *LATTICE quantum chromodynamics, *QUARKS

مستخلص: Determining the existence and the location of the QCD critical point remains a major goal in the heavy-ion collision experiments. A crucial theoretical input for achieving this goal is mapping the QCD equation of state in the presence of baryon chemical potential (μ) which at the moment is limited to small values of μ, away from the critical point. We present a new framework for reconstructing the equation of state from a truncated Taylor series expansion for small μ by using novel resummation techniques. We show how this resummation method can be used to (i) determine the location of the critical point and (ii) constrain the form of the critical contribution to the QCD equation of state which has a direct impact on the shape of the experimental signatures of the critical point. Using the recent lattice data from the HotQCD collaboration we estimate that Tc ≈ 100 MeV, μc ≈ 580 MeV, the crossover slope at the critical point α1 ≈ 9°, and further constrain the non-universal mapping parameters between the Ising model and QCD (scaling) equations of state. [ABSTRACT FROM AUTHOR]

المؤلفون: Neff, Dylan¹ dylan.neff@cea.fr

المصدر: EPJ Web of Conferences. 6/26/2024, Vol. 296, p1-4. 4p.

مصطلحات موضوعية: *QUANTUM chromodynamics, *PROTONS, *FLUCTUATIONS (Physics), *RELATIVISTIC Heavy Ion Collider, *HADRONIC atoms, *LATTICE quantum chromodynamics

مستخلص: The moments of proton and net-proton multiplicity distributions are observables expected to be sensitive to the QCD critical point and the nature of the QCD phase transition from QGP to hadron gas. Hyper-order cumulants are measured in wide centrality bins in STAR BES-I data and found to be qualitatively consistent with trends predicted by lattice QCD which finds a cross-over phase transition at low μB. Data collected at √SNN = 3 GeV in BES-II exhibit trends opposite of those observed in higher energy collisions which may suggest the dominance of hadronic interactions at this energy. The variance of proton multiplicity distributions in azimuthal partitions is measured to search for signals of clustering indicative of a first-order phase transition. A strong dependence on the event multiplicity is observed. This dependence is independent of energy in AMPT while in STAR data a significant trend with energy is observed. [ABSTRACT FROM AUTHOR]

المؤلفون: Hippert, Mauricio¹ hippert@illinois.edu, Grefa, Joaquin^2,3, Manning, T. Andrew⁴, Noronha, Jorge¹, Noronha-Hostler, Jacquelyn¹, Vazquez, Israel Portillo³, Ratti, Claudia³, Rougemont, Rômulo⁵, Trujillo, Michael³

المصدر: EPJ Web of Conferences. 6/26/2024, Vol. 296, p1-4. 4p.

مصطلحات موضوعية: *BAYESIAN analysis, *QUANTUM chromodynamics, *LATTICE quantum chromodynamics, *EINSTEIN-Maxwell equations, *EQUATIONS of state

مستخلص: We present results for a Bayesian analysis of the location of the QCD critical point constrained by first-principles lattice QCD results at zero baryon density. We employ a holographic Einstein-Maxwell-dilaton model of the QCD equation of state, capable of reproducing the latest lattice QCD results at zero and finite baryon chemical potential. Our analysis is carried out for two different parametrizations of this model, resulting in confidence intervals for the critical point location that overlap at one sigma. While samples of the prior distribution may not even predict a critical point, or produce critical points spread around a large region of the phase diagram, posterior samples nearly always present a critical point at chemical potentials of μBc ∼ 550 − 630 MeV. [ABSTRACT FROM AUTHOR]

المؤلفون: Poberezhnyuk, Roman^1,2 rpoberezhnyuk@bitp.kiev.ua, Savchuk, Oleh^1,2,3,4, Vovchenko, Volodymyr⁵, Kuznietsov, Volodymyr^1,2,5, Steinheimer, Jan², Gorenstein, Mark^1,2, Stoecker, Horst^2,4,6

المصدر: EPJ Web of Conferences. 6/26/2024, Vol. 296, p1-5. 5p.

مصطلحات موضوعية: *FLUCTUATIONS (Physics), *LATTICE quantum chromodynamics, *QUANTUM chromodynamics, *COLLISIONS (Nuclear physics), *CUMULANTS

مستخلص: Subensemble Acceptance Method (SAM) [1, 2] is an essential link between measured event-by-event fluctuations and their grand canonical theoretical predictions such as lattice QCD. The method allows quantifying the global conservation law effects in fluctuations. In its basic formulation, SAM requires a sufficiently large system such as created in central nucleus-nucleus collisions and sufficient space-momentum correlations. Directly in the spinodal region of the First Order Phase Transition (FOPT) different approximations should be used that account for finite size effects. Thus, we present the generalization of SAM applicable in both the pure phases, metastable and unstable regions of the phase diagram [3]. Obtained analytic formulas indicate the enhancement of fluctuations due to crossing the spinodal region of FOPT and are tested using molecular dynamics simulations. A rather good agreement is observed. Using transport model calculations with interaction potential we show that the spinodal enhancement of fluctuations survives till the later stages of collision via the memory effect [4]. However, at low collision energies the space-momentum correlation is not strong enough for this signal to be transferred to second and third order cumulants measured in momentum subspace. This result agrees well with recent HADES data on proton number fluctuations at √SNN = 2.4 GeV which are found to be consistent with the binomial momentum space acceptance [5]. [ABSTRACT FROM AUTHOR]

المؤلفون: Karthein, Jamie¹ jmkar@mit.edu

المصدر: EPJ Web of Conferences. 6/26/2024, Vol. 296, p1-6. 6p.

مصطلحات موضوعية: *QUANTUM chromodynamics, *EQUATIONS of state, *THERMODYNAMICS, *LATTICE quantum chromodynamics, *PARTICLE physics

مستخلص: As an important set of thermodynamic quantities, knowledge of the equation of state over a broad range of temperatures and chemical potentials in the QCD phase diagram is crucial for our understanding of strongly-interacting matter. There is a good understanding from first-principles results in lattice QCD, perturbative QCD and chiral effective field theory about the equation of state. However, these approaches are valid in different regimes of the phase diagram, and therefore, a method of providing an equation of state that covers a full range of the phase diagram involves matching together these results with appropriate models in order to fill in the gaps between these regions. Furthermore, with such equations of state, important questions about QCD phase structure can begin to be addressed, such as whether there is a critical point in the QCD phase diagram. In this contribution to the proceedings, equations of state from first-principles and effective theories will be discussed in order to understand how QCD thermodynamics is affected by the presence of a critical point. [ABSTRACT FROM AUTHOR]

المؤلفون: Vovchenko, Volodymyr¹ vvovchenko@uh.edu

المصدر: EPJ Web of Conferences. 6/26/2024, Vol. 296, p1-7. 7p.

مصطلحات موضوعية: *QUANTUM chromodynamics, *LATTICE quantum chromodynamics, *CRITICAL point (Thermodynamics), *CUMULANTS, *PARTICLE physics

مستخلص: We overview recent theoretical developments in the search for QCD critical point at finite temperature and density, including from lattice QCD, effective QCD theories, and proton number cumulants in heavy-ion collisions. We summarize the available constraints and predictions for the critical point location and discuss future challenges and opportunities. [ABSTRACT FROM AUTHOR]