Mass-dependent sequential freeze-out of hadrons

TL;DR

This paper investigates how different hadron species freeze out at different temperatures during the QCD phase transition at low baryonic chemical potential, using fluctuation data and the Hadron Resonance Gas Model.

Contribution

It introduces the concept of mass-dependent sequential freeze-out of hadrons during the QCD phase transition near zero baryonic chemical potential.

Findings

Evidence for mass-dependent freeze-out temperatures of hadrons.

Quantitative analysis of fluctuation data supporting sequential freeze-out.

Study covers center-of-mass energies from 19.6 to 200 GeV/c^2.

Abstract

Fluctuation measurements of hadron yields at heavy-ion collisions can reproduce the phase transition parameters of QCD matter. The fluctuation results produce accurate parameters near zero baryonic chemical potential($\mu_B$) being very sensitive in that region. In this work, using the Hadron Resonance Gas Model(HRG), we determine the freeze-out temperatures of the hadrons using individual fluctuation results and find that sequential freeze-out of hadrons during the QCD phase transition near zero $\mu_B$ is dependent on the mass of produced hadronic species. Using recently published results of net-$\Lambda$ fluctuations and some other fluctuation results, we study the phase diagram at low baryonic chemical potential and center-of-mass energies ranging from 19.6 - 200 GeV/$c^2$ and find significant, quantitative evidence to support our claim.