Indication of a Differential Freeze-out in Proton-Proton and Heavy-Ion Collisions at RHIC and LHC energies

TL;DR

This study analyzes invariant particle spectra from RHIC and LHC collisions using Tsallis distributions, revealing a mass-dependent differential freeze-out and a hierarchy in radial flow, with similar thermodynamics in peripheral heavy-ion and proton-proton collisions.

Contribution

It introduces a detailed analysis of freeze-out parameters across different particle masses and collision types using Tsallis distributions, highlighting a mass-dependent differential freeze-out.

Findings

Mass-dependent differential freeze-out observed

Heavier particles experience lower radial flow

Peripheral A+A and p+p collisions show similar thermodynamic parameters

Abstract

The experimental data from the RHIC and LHC experiments of invariant pT spectra in A+A and p + p collisions are analysed with Tsallis distributions in different approaches. The information about the freeze-out surface in terms of freeze-out volume, temperature, chemical potential and radial flow velocity for different particle species are obtained. Further, these parameters are studied as a function of the mass of the secondary particles. A mass-dependent differential freeze-out is observed which does not seem to distinguish between particles and their antiparticles. Further a mass-hierarchy in the radial flow is observed, meaning heavier particles suffer lower radial flow. Tsallis distribution function at finite chemical potential is used to study the mass dependence of chemical potential. The peripheral heavy-ion and proton-proton collisions at the same energies seem to be equivalent in terms of the extracted thermodynamic parameters.