Thermodynamics of partonic matter in relativistic heavy-ion collisions from a multiphase transport model

TL;DR

This study uses a multiphase transport model to analyze the thermodynamic evolution of partonic matter in heavy-ion collisions across a wide energy range, revealing insights into thermalization and phase boundary trajectories.

Contribution

It introduces a detailed analysis of thermodynamic trajectories and thermalization in partonic matter using a multiphase transport model across various collision energies.

Findings

Trajectories depend on physical factors like nuclear thickness.

Partial thermalization occurs near the QCD phase boundary.

Pressure anisotropy indicates incomplete thermalization.

Abstract

Using the string melting version of a multiphase transport model, we focus on the evolution of thermodynamic properties of the central cell of parton matter produced in Au$+$Au collisions ranging from 200 GeV down to 2.7 GeV. The temperature and chemical potentials have been calculated based on both Boltzmann and quantum statistics in order to locate their evolution trajectories in the QCD phase diagram. We demonstrate that the trajectories can depend on many physical factors, especially the finite nuclear thickness at lower energies. However, from the evolution of pressure anisotropy, only partial thermalization can be achieved when the partonic systems reach the predicted QCD phase boundary. It provides some helpful insights to studying the QCD phase structure through relativistic heavy-ion collisions.