Anisotropic flow and flow fluctuations for Au + Au at $\sqrt{s_{NN}}$ = 200 GeV in a multiphase transport model

TL;DR

This study uses a multi-phase transport model to analyze anisotropic flow coefficients and their fluctuations in Au+Au collisions at 200 GeV, successfully reproducing experimental results and revealing the dominant role of partonic evolution in flow fluctuations.

Contribution

It provides a detailed event-by-event analysis of flow fluctuations and their dependencies, highlighting the impact of parton cascade processes on flow variability.

Findings

Flow coefficients follow Gaussian distributions across centralities.

Parton cascade significantly influences flow fluctuations.

Hadronic rescatterings have minimal effect on flow fluctuations.

Abstract

Anisotropic flow coefficients and their fluctuations are investigated for Au+Au collisions at center of mass energy $\sqrt{s_{NN}}$ = 200 GeV by using a multi-phase transport model with string melting scenario. Experimental results of azimuthal anisotropies by means of the two- and four-particle cumulants are generally well reproduced by the model including both parton cascade and hadronic rescatterings. Event-by-event treatments of the harmonic flow coefficients $v_n$ (for n = 2, 3 and 4) are performed, in which event distributions of $v_n$ for different orders are consistent with Gaussian shapes over all centrality bins. Systematic studies on centrality, transverse momentum ($p_{T}$) and pseudo-rapidity ($\eta$) dependencies of anisotropic flows and quantitative estimations of the flow fluctuations are presented. The $p_{T}$ and $\eta$ dependencies of absolute fluctuations for both $v_2$ and $v_3$ follow similar trends as their flow coefficients. Relative fluctuation of triangular flow $v_3$ is slightly centrality-dependent, which is quite different from that of elliptic flow $v_2$. It is observed that parton cascade has a large effect on the flow fluctuations, but hadronic scatterings make little contribution to the flow fluctuations, which indicates flow fluctuations are mainly modified during partonic evolution stage.