Specific heat and its high-order moments in relativistic heavy-ion collisions from a multiphase transport model

TL;DR

This study investigates the energy dependence of specific heat in relativistic heavy-ion collisions using a multiphase transport model, introducing a new quantity to better understand the thermal properties of hot dense QCD matter.

Contribution

A new quantity $C_v^{*}$ and its high-order moments are proposed to describe specific heat and thermal properties in heavy-ion collisions, distinguishing different phases.

Findings

Differences in specific heat at low collision energies were observed.

The new quantity $C_v^{*}$ effectively characterizes the thermal properties of the hot dense matter.

High-order moments of $C_v^{*}$ can differentiate phases with or without parton processes.

Abstract

Energy dependence of specific heat extracted from temperature fluctuation of Au + Au collisions at $\sqrt{s_{NN}}$ = 7.7 GeV to 200 GeV was investigated by using a multiphase transport (AMPT) model. The results were compared with those from other models and some differences at low $\sqrt{s_{NN}}$ were found. To explain the above differences and describe the properties of the hot dense matter at low $\sqrt{s_{NN}}$, a new quantity $C_v^{*}$ was derived for describing specific heat in heavy-ion collisions. It was found that, by using $C_v^{*}$ together with its high order moments (skewness and kurtosis), thermal properties of the hot dense matter can be described and different thermal properties with or without parton process can be clearly distinguished. The proposed observable provides a way to learn the property of QCD matter % phase transition %along with critical point in heavy-ion collisions.