Hadronic Freeze-Out in A+A Collisions meets the Lattice QCD Parton-Hadron Transition Line

TL;DR

This study investigates the hadronization process in heavy-ion collisions, showing that after accounting for hadronic interactions, the freeze-out points align with lattice QCD predictions of the parton-hadron transition line.

Contribution

It introduces a method to incorporate hadronic rescattering effects into statistical model analyses, aligning experimental freeze-out data with lattice QCD transition predictions.

Findings

Bulk meson yields freeze out at hadronization.

Baryon-antibaryon sector is significantly affected by annihilation and regeneration.

Modified statistical model aligns freeze-out points with lattice QCD transition line.

Abstract

We analyze hadrochemical freeze-out in central Pb+Pb collisions at CERN SPS and LHC energies. Employing the UrQMD hybrid transport model we study the effects of the final hadron/resonance expansion phase on the hadron multiplicities established at hadronization. The bulk meson yields freeze out directly at hadronization whereas the baryon-antibaryon sector is subject to significant alterations, due to annihilation and regeneration processes. We quantify the latter changes by survival factors for each species which are applied to modify the statistical model predictions for the data. The modified SM analysis recovers the hadronization points, which coincide with the recent lattice QCD predictions of the parton-hadron transition line at finite baryochemical potential.