Study of Dependence of Kinetic Freezeout Temperature on the Production Cross-Section of Particles in Various Centrality Intervals in Au-Au and Pb-Pb Collisions at High Energies.

Muhammad Waqas,Guang-Xiong Peng

doi:10.3390/e23040488

Abstract

Transverse momentum spectra of , p, , or , or and deuteron (d) in different centrality intervals in nucleus–nucleus collisions at the center of mass energy are analyzed by the blast wave model with Boltzmann Gibbs statistics. We extracted the kinetic freezeout temperature, transverse flow velocity and kinetic freezeout volume from the transverse momentum spectra of the particles. It is observed that the non-strange and strange (multi-strange) particles freezeout separately due to different reaction cross-sections. While the freezeout volume and transverse flow velocity are mass dependent, they decrease with the resting mass of the particles. The present work reveals the scenario of a double kinetic freezeout in nucleus–nucleus collisions. Furthermore, the kinetic freezeout temperature and freezeout volume are larger in central collisions than peripheral collisions. However, the transverse flow velocity remains almost unchanged from central to peripheral collisions.

Highlights

IntroductionFreezeout stages are very important because they provide essential information about the emissions of the particles at those stages
The symbols are cited from the experimental data measured by the STAR Collaboration at the Relativistic Heavy Ion Collider (RHIC) [21,55,56]
One can see that the p T spectra of the particles are shown to obey approximately the blast wave model with Boltzmann Gibbs statistics

Summary

Introduction

Freezeout stages are very important because they provide essential information about the emissions of the particles at those stages. The chemical freezeout is the intermediate stage in high-energy collisions where the intra-nuclear collisions between the particles are inelastic and the ratio of various types of particles remain unchanged; the temperature of the particles at this stage is the chemical freezeout temperature, which describes the excitation degree of the system at the chemical freezeout stage. The thermal/kinetic freezeout is the last stage in high-energy collisions. At this stage, the intra-nuclear collisions between the particles are elastic. The transverse momentum distributions of various kinds of particles are no longer changed at the thermal freezeout stage, and the temperature at this stage is called the kinetic freezeout temperature

Methods

Results

Conclusion