分类: 物理学 >> 核物理学 提交时间: 2023-10-23
摘要: The pseudo-rapidity distributions of the charged particles produced in the asymmetric collision systems p+Al, p+Au and $^3$He+Au at $ sqrt{s_{NN}} = 200$ GeV are evaluated in the framework of a fireball model with Tsallis thermodynamics. The fireball model assumes that the experimentally measured particles are produced by fireballs following the Tsallis distribution and it can effectively describe the experimental data. Our results as well as previous results for d+Au collisions at $ sqrt{s_{NN}} = 200$ GeV and p+Pb collisions at $ sqrt{s_{NN}} = 5.02$ TeV validate that the fireball model based on Tsallis thermodynamics can provide a universal framework for pseudo-rapidity distribution of the charged particles produced in asymmetric collision systems. We predict the centrality dependence of the total charged particle multiplicity in the p+Al, p+Au and $^3$He+Au collisions. Additionally, the dependences of the fireball model parameters ($y_{0a}$, $y_{0A}$, $ sigma_{a}$ and $ sigma_{A}$) on the centrality and system size are studied.
分类: 物理学 >> 核物理学 提交时间: 2023-09-07
摘要: The thermodynamic properties of charged particles, such as the energy density, pressure, entropy density, particle density, and squared speed of sound at the kinetic freeze-out in the $ mathrm{Au+Au}$ collisions from the relativistic heavy ion collider (RHIC) beam energy scan program ($ sqrt{s_ text{NN}}$=7.7--200 GeV) and in the $ mathrm{Cu+Cu}$ collisions at $ sqrt{s_ text{NN}}$=62.4, 200 GeV are studied using the thermodynamically consistent Tsallis distribution. The energy density, pressure, and particle density decrease monotonically with the collision energy for the same collision centrality; These properties also decrease monotonically from the central to peripheral collisions at the same collision energy. While the scaled energy density $ varepsilon/T^4$ and scaled entropy density $s/T^3$ demonstrate the opposite trend with the collision energy for the same collision centrality. There is a correlation between $ varepsilon/T^4$ and $s/T^3$ at the same centrality. In addition, the squared speed of sound was calculated to determine that all the collision energies share nearly the same value at different collision centralities.