Study of Proton, Deuteron, and Triton at 54.4 GeV

M Waqas,G X Peng,Enrico Lunghi

doi:10.1155/2021/6674470

Abstract

Transverse momentum spectra of proton, deuteron, and triton in gold-gold (Au-Au) collisions at 54.4 GeV are analyzed in different centrality bins by the blast wave model with Tsallis statistics. The model results are approximately in agreement with the experimental data measured by STAR Collaboration in special transverse momentum ranges. We extracted the kinetic freeze-out temperature, transverse flow velocity, and freeze-out volume from the transverse momentum spectra of the particles. It is observed that the kinetic freeze-out temperature is increasing from the central to peripheral collisions. However, the transverse flow velocity and freeze-out volume decrease from the central to peripheral collisions. The present work reveals the mass dependent kinetic freeze-out scenario and volume differential freeze-out scenario in collisions at STAR Collaboration. In addition, parameter q characterizes the degree of nonequilibrium of the produced system, and it increases from the central to peripheral collisions and increases with mass .

Highlights

The two important stages in the evolution system are chemical and kinetic freeze-out
The transverse momentum spectra of different particles are no longer changed at the stage of kinetic freeze-out and thermal/kinetic freeze-out temperature can be obtained from the transverse momentum spectra according to the hydrodynamical model [4]
From number of strings’ point of view, the maximum number of strings is in the second presents the transverse momentum (pT) region that results in fusion and creation of strings and collective behavior of partons

Summary

Introduction

The two important stages in the evolution system are chemical and kinetic freeze-out. The degree of excitation of the interacting system at the two stages is different from each other. The chemical and kinetic freeze-out temperatures are used to describe different excitation degrees of interacting system of the two stages. The ratios of different kinds of particles are no longer changed at the stage of chemical freeze-out. The chemical freeze-out temperature can be obtained from different particle ratios in the framework of the thermal model [1,2,3]. The transverse momentum spectra of different particles are no longer changed at the stage of kinetic freeze-out and thermal/kinetic freeze-out temperature can be obtained from the transverse momentum spectra according to the hydrodynamical model [4]

Methods

Results

Discussion

Conclusion