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

Abstract

Energy dependence of specific heat extracted from temperature fluctuation of Au + Au collisions at $\sqrt{{s}_{NN}}$ = 7.7 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 in heavy-ion collisions.