Freezeout properties of different light nuclei at the RHIC Beam Energy Scan

TL;DR

This study analyzes light nuclei production in Au-Au collisions at RHIC energies using a blast wave model with Tsallis statistics, revealing freezeout properties and potential phase transition signals in the 14.5-39 GeV energy range.

Contribution

It introduces a detailed analysis of light nuclei freezeout parameters across energies and centralities, suggesting phase transition onset and critical point location in RHIC energy scan.

Findings

Freezeout temperature and flow velocity increase then saturate with energy.

Kinetic freezeout volume saturates above 19.6 GeV.

Triton freezes out earlier than deuteron and anti-deuteron.

Abstract

We study the transverse momentum spectra of light nuclei (deuteron, anti-deuteron and triton) produced in Gold-Gold (Au-Au) collisions in different centrality bins by the blast wave model with Tsallis statistics. The model results are in agreement with the experimental data measured by STAR Collaboration in special transverse momentum ranges. We extracted the kinetic freezeout temperature, transverse flow velocity and kinetic freezeout volume. It is observed that kinetic freezeout temperature and transverse flow velocity increases initially, and then saturates from 14.5-39 GeV, while the kinetic freezeout volume increase initially up to 19.6 GeV but saturates from 19.6-39 GeV. This may indicate that the phase transition starts in part volume that ends in the whole volume at 39 GeV and the critical point may exists somewhere in the energy range of 14.5-39 GeV. The present work observed that the kinetic freezeout temperature, transverse flow velocity and kinetic freezeout volume has a decreasing trend from central to peripheral collisions. We found the freezeout volume of triton is smaller than those of deuteron and anti-deuteron, which shows that triton freezeout earlier than that of deuteron and anti-deuteron.