Reconstructing the final state of Pb+Pb collisions at $\sqrt{s_{NN}}=2.76$ TeV

Abstract

We fit the single-hadron transverse-momentum spectra measured in Pb+Pb collisions at $\sqrt{s_{NN}} = 2.76$ TeV with the blast-wave model that includes production via resonance decays. Common fit to pions, kaons, (anti)protons, and lambdas yields centrality dependence of the freeze-out temperature and transverse expansion velocity. In the most central collisions we see $T=98$ MeV and $\langle v_t \rangle = 0.654$. The $K^*$ resonance fits into this picture but the $\phi$ meson might freeze-out a little earlier. Multistrange baryons seem to decouple at higher temperature and weaker transverse flow. Within our model we observe hints of chemical potential for the charged pions.