Mass-dependent sequential freeze-out of hadrons

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.