Effect of Light Nuclei on Chemical Freeze-out Parameters at RHIC Energies

Abstract

In this study, the chemical freeze-out of hadrons, including light-and strange-flavor particles and light nuclei, produced in Au+Au collisions at the Relativistic Heavy Ion Collider (RHIC), was investigated. Using the thermal-FIST thermodynamic statistical model, we analyzed various particle sets: those inclusive of light nuclei, those exclusive to light nuclei, and those solely comprising light nuclei. We determined the chemical freeze-out parameters at $\sqrt{s_{\text{NN}}}=$ 7.7--200 GeV and four different centralities. A significant finding was the decrease in the chemical freeze-out temperature $T_{\text{ch}}$ with light nuclei inclusion, with an even more pronounced reduction when considering light nuclei yields exclusively. This suggests that light nuclei formation occurs at a later stage in the system's evolution at RHIC energies. We present parameterized formulas that describe the energy dependence of $T_{\text{ch}}$ and the baryon chemical potential ${\mu }_B$ for three distinct particle sets in central Au+Au collisions at RHIC energies. Our results reveal at least three distinct $T_{\text{ch}}$ at RHIC energies correspond to different freeze-out hypersurfaces: a light-flavor freeze-out temperature of $T_L$ = 150.2$\pm$6 MeV, a strange-flavor freeze-out temperature $T_s$ = 165.1$\pm$2.7 MeV, and a light-nuclei freeze-out temperature $T_{\text{ln}}$ = 141.7$\pm$1.4 MeV. Notably, at the Large Hadron Collider (LHC) Pb+Pb 2.76 TeV, the expected lower freeze-out temperature for light nuclei was not observed; instead, the $T_{\text{ch}}$ for light nuclei was found to be approximately 10 MeV higher than that for light-flavor hadrons.

9 pages, 6 figures

References in corpus (9)

• Systematic Measurements of Identified Particle Spectra in pp, d+Au and Au+Au Collisions from STAR
• Strange and Multi-strange Particle Production in Au+Au Collisions at $\sqrt{s_{NN}}$ = 62.4 GeV
• Beam energy dependence of (anti-)deuteron production in Au+Au collisions at RHIC
• Beam Energy Dependence of Triton Production and Yield Ratio (${\mathrm{N}}_t\times {\mathrm{N}}_p/{\mathrm{N}}_d^2$) in Au+Au Collisions at RHIC
• Multiplicity Scaling of Light Nuclei Production in Relativistic Heavy-Ion Collisions
• Effects of a phase transition on two-pion interferometry in heavy-ion collisions at $\sqrt{s_{\mathrm{NN}}}=2.4-7.7$ GeV
• Flavour and Energy Dependence of Chemical Freeze-out Temperatures in Relativistic Heavy Ion Collisions from RHIC-BES to LHC Energies
• Light (anti)nuclei production in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV
• Measurements of chemical potentials in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV

Cited by in corpus (2)

• Reconstructing rare particle source by femtoscopic correlations
• Flavour-Dependent Chemical Freeze-Out of Light Nuclei in Relativistic Heavy-Ion Collisions