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

Understand

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.