Effects of volume corrections and resonance decays on cumulants of net-charge distributions in a Monte Carlo hadron resonance gas model

Abstract

The effects of volume corrections and resonance decays (the resulting correlations between positive charges and negative charges) on cumulants of net-proton distributions and net-charge distributions are investigated by using a Monte Carlo hadron resonance gas ({\tt MCHRG}) model. The required volume distributions are generated by a Monte Carlo Glauber ({\tt MC-Glb}) model. Except the variances of net-charge distributions, the {\tt MCHRG} model with more realistic simulations of volume corrections, resonance decays and acceptance cuts can reasonably explain the data of cumulants of net-proton distributions and net-charge distributions reported by the STAR collaboration. The {\tt MCHRG} calculations indicate that both the volume corrections and resonance decays make the cumulant products of net-charge distributions deviate from the Skellam expectations: the deviations of $S\sigma$ and $\kappa {\sigma }^2$ are dominated by the former effect while the deviations of $\omega$ are dominated by the latter one.

Comments: A Monte Carlo hadron resonance gas (MCHRG) model is proposed to study the cumulants of multiplicity distributions. 6 pages, 2 figures