Particle species and energy dependencies of freeze-out parameters in high-energy proton-proton collisions

TL;DR

This study analyzes proton-proton collision data at the LHC using a blast wave model with Tsallis statistics to extract freeze-out parameters, revealing mass and energy dependencies and simultaneous freeze-out of certain light nuclei due to isospin symmetry.

Contribution

It introduces a detailed analysis of freeze-out parameters in high-energy proton-proton collisions considering mass and energy dependencies using a combined blast wave and Tsallis model.

Findings

Kinetic freeze-out temperature increases with particle mass.

Kinetic freeze-out volume decreases with particle mass.

Certain light nuclei freeze-out simultaneously due to isospin symmetry.

Abstract

We used blast wave model with Tsallis statistics to analyze the experimental data measured by ALICE Collaboration in proton-proton collisions at Large Hadron Collider and extracted the related parameters (kinetic freeze-out temperature, transverse flow velocity and kinetic freeze-out volume of emission source) from transverse momentum spectra of the particles. We found that the kinetic freeze-out temperature and kinetic freeze-out volume are mass dependent. The former increase while the latter decrease with the particle mass which is the evidence of a mass as well as volume differential kinetic freeze-out scenario. Furthermore we extracted the mean transverse momentum and initial temperature by an indirect method and observed that they increase with mass of the particles. All the above discussed parameters are observed to increase with energy. Triton ($t$), hyper-triton (${^3_{\bar\Lambda} H}$) and helion (${^3 He}$) and their anti-matter are observed to freeze-out at the same time due to isospin symmetry.