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

TL;DR

This study uses a Monte Carlo hadron resonance gas model to analyze how volume corrections and resonance decays influence cumulants of net-charge and net-proton distributions, aligning with experimental data from STAR.

Contribution

It introduces a more realistic simulation approach combining volume corrections and resonance decays to explain cumulant measurements in heavy-ion collisions.

Findings

Volume corrections and resonance decays significantly affect cumulant ratios.

The model explains deviations from Skellam expectations in experimental data.

Resonance decays mainly influence the variance-related cumulants.

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.