Energy density at kinetic freeze-out in Pb-Pb collisions at the LHC using the Tsallis distribution

TL;DR

This study analyzes the energy density at kinetic freeze-out in Pb-Pb collisions at the LHC using the Tsallis distribution, revealing how thermodynamic parameters evolve with collision centrality and energy.

Contribution

It provides the first detailed determination of energy density at kinetic freeze-out in Pb-Pb collisions at LHC energies using the Tsallis distribution.

Findings

Energy density at freeze-out reaches about 0.039 GeV/fm³ for central collisions.

Energy density decreases following a T^4 law from chemical to kinetic freeze-out.

Pressure and entropy density vary with centrality and collision energy.

Abstract

The thermodynamic parameters like energy density, pressure, entropy density, temperature and particle density are determined from the transverse momentum distributions of charged particles in Pb-Pb collisions at the LHC. The results show a clear increase with the centrality and the beam energy in all parameters. It is determined that in the final freeze-out stage the energy density reaches a value of about 0.039 GeV/fm$^3$ for the most central collisions at $\sqrt{s_{NN}}$ = 5.02 TeV. This is less than that at chemical freeze-out where the energy density is about 0.36 GeV/fm$^3$. This decrease approximately follows a $T^4$ law. The results for the pressure and entropy density are also presented for each centrality class at $\sqrt{s_{NN}}$ = 2.76 and 5.02 TeV.