Study on higher moments of net-charge multiplicity distributions using a multiphase transport model * *Supported in part by the Strategic Priority Research Program of Chinese Academy of Sciences (XDB34030000), the National Natural Science Foundation of China (11890710, 11890714, 11835002, 11961131011) and the Guangdong Major Project of Basic and Applied Basic Research (2020B0301030008)

Abstract

The moments and moment products of conserved charges are believed to be sensitive to critical fluctuations, which have been adopted in determining the QCD critical point. Using a dynamical multiphase transport model, we reproduce the centrality and energy dependences of moments and moment products of net-charge multiplicity distributions in Au+Au collisions, measured by the Beam Energy Scan program at the RHIC. No non-monotonic energy dependence is observed. We infer that the moment products develop during the dynamical evolution of heavy-ion collisions. The observed difference based on the expectation of the Poisson baseline indicates a positive two-particle correlation between positively and negatively charged particles, which can arise from different dynamical processes at different stages. Therefore, to adopt moments and moment products of net-charge multiplicity distributions in determining the QCD critical point of relativistic heavy-ion collisions, it is essential to consider the dynamical evolution.