Dynamical development of proton cumulants and correlation functions in Au+Au collisions at $\sqrt{s_{NN}} = 7.7$ GeV from a multiphase transport model

TL;DR

This study uses a multiphase transport model to analyze proton cumulants and correlations in Au+Au collisions at 7.7 GeV, providing insights into QCD phase transition signals and establishing a baseline for critical point searches.

Contribution

It offers the first detailed calculation of proton and net-proton cumulants and correlations at this energy using the AMPT model, aligning with experimental trends and highlighting dynamical effects.

Findings

AMPT model reproduces experimental cumulant trends

Proton correlations are consistent with baryon number conservation

Correlations are affected by collision dynamics

Abstract

Higher-order cumulants of the distributions of conserved charges, such as net-baryon number, are sensitive to the quantum chromodynamics(QCD) phase transition and the QCD critical point. We calculate the cumulants and correlation functions of proton, antiproton, and net-proton multiplicity distributions in Au+Au collisions at $\sqrt{s_{NN}} = 7.7$ GeV using a multiphase transport model(AMPT). The AMPT model can basically describe the trends of cumulants, cumulant ratios, (normalized) correlation functions of the proton and net-proton measured by the STAR experiment. The multiproton (baryon) correlations in the AMPT model are consistent with the expectation from baryon number conservation. We demonstrate that multiproton (baryon) correlations suffer the dynamical evolution of heavy-ion collisions. Our results provide a baseline for searching for the possible critical behaviors at the critical end point in relativistic heavy-ion collisions.