Universal Freezeout Condition for Charged Hadrons in a Hybrid Approach

TL;DR

This paper introduces a hybrid model combining Tsallis statistics and wounded quark approach to identify a universal freezeout condition in heavy-ion collisions by analyzing the ratio of transverse energy to charged particle multiplicity.

Contribution

The paper develops a hybrid model that accurately reproduces experimental data and proposes a universal freezeout criterion based on the ratio $E_{T}/N_{ch}$ in heavy-ion collisions.

Findings

The hybrid model successfully explains $dE_{T}/dta$ distributions across different collision types.

The ratio $E_{T}/N_{ch}$ shows no explicit dependence on energy or centrality.

$E_{T}/N_{ch}$ can serve as a universal freezeout condition.

Abstract

Hadronic freezeout during the evolution of the medium created in heavy-ion collisions is an important phenomena. It is quite useful to find a universal freezeout condition for each and every nuclear collisions. In this article, we have constructed a hybrid model to calculate the ratio of transverse energy to total mean multiplicity $E_{T} /N_{ch}$, since this ratio can possibly act as a freezeout condition in heavy-ion collision experiments. Present hybrid model blends two approaches : Tsallis statistics and wounded quark approach. Recently, Tsallis statistics has been reliably used to obtain the transverse momentum distribution of charged hadrons produced in relativistic ion collisions. On the other side it has been shown that the pseudorapidity distribution of charged hadrons can be calculated satisfactorily using the wounded quark model (WQM). We have used this hybrid model to calculate the transverse energy density distributions, $dE_{T}/d\eta$ at midrapidity using charged particle pseudorapidity distributions, $dN_{ch}/d\eta$ and mean transverse momentum $\langle p_{T} \rangle$ in various type of nuclear collisions. We found that present hybrid model satisfactorily explains the experimental data whether other models fail to reproduce the data at central and at peripheral collisions simultaneously. Finally, ratio of transverse energy to total mean multiplicity, $E_{T} /N_{ch}$ has been computed within hybrid model and compared with the available experimental data at RHIC and LHC energies. We observed no explicit dependence of $E_{T} /N_{ch}$ on energy as well as centrality and thus it can definitely act as a freezeout criteria.