Measurement of cumulants of conserved charge multiplicity distributions in Au+Au collisions from the STAR experiment

Abstract: We report the collision-centrality dependence of cumulants of event-by-event net-proton, net-charge and net-kaon distributions in Au+Au collisions for center-of-mass energy $\sqrt{s_{NN}}$ = 54.4 GeV from the STAR experiment. Strong collision-centrality dependence is observed for cumulants ($C_{n}, n$ $\leq$ 4) of the net-particle distributions. The cumulant ratios $C_{3}/C_{2}$, $C_{4}/C_{2}$ and $C_{6}/C_{2}$ exhibit a weak collision-centrality dependence. The $C_{6}/C_{2}$ of net-proton and net-charge distributions for most central gold nuclei collisions at $\sqrt{s_{NN}}$ = 54.4 GeV show positive sign while they remain negative at 200 GeV for the same collision system. To understand effects of acceptance and baryon number conservation, the measurements are compared to expectations from the UrQMD and HIJING models calculated within the STAR detector acceptance.