Net-baryon number fluctuations with the hadron resonance gas model using Tsallis distribution

Abstract

We explore a hadron resonance gas model using Tsallis non-extensive distribution to study the energy dependence of the product of the moments, $S\sigma$ and $\kappa\sigma^2$ of net-proton multiplicity distributions of published STAR data in \auau collisions at relativistic heavy-ion collider (RHIC) energies. While excellent agreements are found between model predictions and measurements of $S\sigma$ and $\kappa \sigma^2$ of most peripheral collisions and $S\sigma$ of most central collisions, the $\kappa \sigma^2$ for most central collisions deviates significantly from the predictions particularly at \sqsn = 19.6 GeV and $27$ GeV. This could be an indication of the presence of dynamical fluctuations, which are not contained in the HRG-Tsallis model.