Centrality fluctuations and decorrelations in heavy-ion collisions in a Glauber model
Not Available
Jia, Jiangyong (ORCID:0000000257253397)↗
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Signatures of QCD conductivities in heavy-ion collisions
Dissipative processes are pivotal for understanding the hydrodynamic evolution of hot and dense quantum chromodynamics (QCD) matter created in relativistic nuclear collisions. The interplay of multiple conserved charges—net baryon, strangeness, and electric charge—is of particular interest. Here, we simulate the longitudinal hydrodynamic evolution with the three diffusion currents in a hydrodynamic model with a lattice-QCD-based equation of state, NEOS -4 D , and estimate rapidity distributions including diffusive corrections to the phase-space distribution in the presence of multiple charges, which ensure charge conservation at particlization. We determine the response of particle yields at midrapidity to changes in the diagonal and off-diagonal conductivities. Inversely, we find that most components of the conductivity matrix can be constrained experimentally using identified particle multiplicities at different collision energies.
73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
Conglomerate Multi-fidelity Gaussian Process Modeling, with Application to Heavy-Ion Collisions
Not provided.
Mathematics↗
Magnetic fields in heavy ion collisions: flow and charge transport
Not Available
73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
Scaling properties of direct photon yields in heavy ion collisions
Abstract A recent analysis from the PHENIX collaboration of available direct photon measurement results in collisions of various systems such as Au+Au, Cu+Cu, and Pb+Pb, at different beam energies ranging from 39 to 2760 GeV, has shown a universal, within experimental uncertainties, multiplicity scaling, in which direct photon $$p_{T}$$ p T -spectra for transverse momenta up to 2 GeV/ c are scaled with charged hadron pseudorapidity density at midrapidity raised to power $$\alpha =1.25$$ α = 1.25 . On the other hand, those direct photon $$p_{T}$$ p T -spectra also exhibit geometrical scaling in the similar $$p_{T}$$ p T range. Assuming power-law dependence of the scaled photon spectra for both scaling laws, we formulate two independent conditions for the power $$\alpha $$ α , which overshoot experimental data by $$\sim 10\%$$ ∼ 10 % on average. We discuss possible sources that might improve this estimate.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
Fireball tomography from bottomonia elliptic flow in relativistic heavy-ion collisions
Abstract We calculate the elliptic flow of bottomonia produced in Pb $$\,+\,$$ + Pb collisions at $$\sqrt{s_{\mathrm{NN}}}=5.02$$ s NN = 5.02 TeV. We consider temperature-dependent decay widths for the anisotropic escape of various bottomonium states and observe that the transverse momentum dependence of bottomonia elliptic flow provides a tomographic information about the QGP fireball at different stages of its evolution. For the space-time evolution of the fireball, we employ simulation results from the 3 + 1 D quasiparticle anisotropic hydrodynamic model. We find that our results for transverse momentum dependence of bottomonia elliptic flow are in reasonable agreement with experimental results from the ALICE and CMS collaborations.
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
Polarization phenomenon in heavy-ion collisions
The strongly interacting system created in ultrarelativistic nuclear collisions behaves almost as an ideal fluid with rich patterns of the velocity field exhibiting strong vortical structure. Vorticity of the fluid, via spin-orbit coupling, leads to particle spin polarization. Due to the finite orbital momentum of the system, the polarization on average is not zero. It depends on the particle momenta reflecting the spatial variation of the local vorticity. In the last few years, this field experienced a rapid growth due to experimental discoveries of the global and local polarizations. Recent measurements triggered further development of the theoretical description of the spin dynamics and suggestions of several new mechanisms for particle polarization. In this review, we focus mostly on the experimental results. We compare the measurements with the existing theoretical calculations but try to keep the discussion of possible underlying physics at the qualitative level. Future measurements and how they can help to answer open theoretical questions are also discussed. We pay a special attention to the employed experimental methods, as well as to the detector effects and associated corrections to the measurements.
Physics↗
Exploring new small system geometries in heavy ion collisions [Slides]
We explore various new collision geometries in the context of the publicly available hydrodynamic model SONIC. We incorporate full A-nucleon configurations for 4 He, 12 C, and 16 O obtained from quantum Monte Carlo calculations with realistic nuclear potentials, and use a Monte Carlo Glauber calculation for the initial conditions.
73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
Studies of Heavy Ion Collisions in Stochastic Mean Field Approach Under DOE Grant Number DE-SC0015 (Final report)
This is the final report on DOE Grant No. DE-SC0015513, which was active at Tennessee Technological University (TTU) from May 1, 2016 to April 30, 2023. This report provides an overall summary of the more detailed activities presented in progress reports, covering Budget Periods May 1, 2016- April 30, 2017; May 1, 2017- April 30, 2018; May 1, 2019- April 30, 2020; May 1, 2020- April 30, 2021 and May 1, 2021- April 30, 2022, which were submitted annually to the DOE Office of Nuclear Physics. During the no-cost extension period starting May 1, 2022, our investigations of multi-nucleon exchange mechanism and description of kinetic energy dissipation and fluctuations in Cf250+TH232 and Pb208+Pb208 quasi-fission reactions are in progress.
73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
Dense Nuclear Matter Equation of State from Heavy-Ion Collisions
The nuclear equation of state (EOS) is at the center of numerous theoretical and experimental efforts in nuclear physics, motivated by its crucial role in our understanding of the properties of nuclear matter found on Earth, in neutron stars, and in neutron-star mergers. With advances in microscopic theories for nuclear interactions, the availability of experiments probing nuclear matter under conditions not reached before, and the advent of multi-messenger astronomy, the next decade will bring new opportunities for determining the nuclear matter EOS.
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
The Novel Scaling of Tsallis Parameters from the Transverse Momentum Spectra of Charged Particles in Heavy-Ion Collisions
The transverse momentum (pT) spectra of charged particles measured in Au + Au collisions from the beam energy scan (BES) program, Cu + Cu collisions at sNN=62.4, 200 GeV at the RHIC and Pb + Pb, Xe + Xe collisions at the LHC are investigated in the framework of Tsallis thermodynamics. The theory can describe the experimental data well for all the collision systems, energies and centralities investigated. The collision energy and centrality dependence of the Tsallis distribution parameters, i.e., the temperature T and the nonextensive parameter q, for the A + A collisions are also studied and discussed. A novel scaling between the temperature divided by the natural logarithm of collision energy (T/lns) and the nonextensive parameter q is presented.
Tao, Junqi↗
Long Range Plan: Dense matter theory for heavy-ion collisions and neutron stars
Since the release of the 2015 Long Range Plan in Nuclear Physics, major events have occurred that reshaped our understanding of quantum chromodynamics (QCD) and nuclear matter at large densities, in and out of equilibrium. The US nuclear community has an opportunity to capitalize on advances in astrophysical observations and nuclear experiments and engage in an interdisciplinary effort in the theory of dense baryonic matter that connects low- and high-energy nuclear physics, astrophysics, gravitational waves physics, and data science. This is a white paper prepared by a group of nuclear physicists during the 2023 LRP process.
Lovato, Alessandro↗
Production of Exotic Hadrons and Perspectives for Heavy Ion Collisions
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Durham, J. Matthew↗
Probing early parton emissions in heavy ion collisions using the Lund jet plane
In scattering experiments, high-virtuality partons, i.e., quarks and gluons, initiate a series of additional parton emissions to create collimated sprays of particles known as jets. This paper presents a measurement of the Lund jet plane (LJP) of high-energy jets produced in lead-lead (PbPb) collisions and compares the results to data for proton-proton (pp) collisions. The LJP is formed by iteratively declustering the constituents of a jet into consecutive emissions and recording the relative transverse momentum ($k_\mathrm{T}$) and angle of the resulting emission with respect to its emitter. The angular distributions of two different $k_\mathrm{T}$ slices of the LJP are investigated for jets with radius parameter of 0.4 and transverse momentum in the range 200$-$1000 GeV. The PbPb (pp) data were recorded by the CMS experiment in 2018 (2017) and correspond to an integrated luminosity of 1.7 nb$^{-1}$ (301 pb$^{-1}$) at a nucleon-nucleon center-of-mass energy of 5.02 TeV. The measurement was designed to test whether the earliest jet emissions are produced before the formation of the quark-gluon plasma (QGP) in PbPb collisions. Within the experimental uncertainties, no significant difference is observed between the angular distribution of high-$k_\mathrm{T}$ emissions in \pp and PbPb collisions, which is consistent with these emissions occurring early in the jet evolution, before substantial interaction with the QGP.
Belyaev, Andrey [Yerevan Phys. Inst.] (ORCID:00000↗
Symmetry-energy expansion with strange dense matter
The quantum chromodynamics (QCD) phase diagram at large densities and low temperatures can be probed using both neutron stars and low-energy heavy-ion collisions. Heavy-ion collisions are nearly isospin-symmetric systems, whereas neutron stars are highly isospin asymmetric since they are neutron rich. The symmetry-energy expansion is used to connect these regimes across isospin asymmetry. However, the current symmetry-energy expansion does not account for strange particles. In this work, we include finite strangeness by redefining the isospin-asymmetry parameter and the symmetry-energy expansion in a way that is consistent with QCD SU(3) flavor symmetry. Furthermore, our new symmetry energy works well beyond typical neutron star central densities and admits a skewness term in the presence of strangeness for the case of weak equilibrium.
Equations of state of nuclear matter↗
Phenomenological implications of asymmetric AdS 5 shock wave collision studies for heavy ion physics
Not Available
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗