Particle Production at RHIC and LHC Energies

TL;DR

This paper compares particle production ratios in heavy-ion collisions at RHIC and LHC energies with predictions from the HRG model and PYTHIA, revealing areas of agreement and discrepancy in strange and non-strange particle yields.

Contribution

It provides a detailed comparison of experimental particle ratios with theoretical models, highlighting limitations of HRG and PYTHIA in describing strange particle production.

Findings

Particle-to-antiparticle ratios are well reproduced by HRG and PYTHIA.

HRG overestimates kaon-to-pion and proton-to-pion ratios.

PYTHIA underestimates kaon-to-pion ratio but accurately reproduces proton-to-pion ratio.

Abstract

The production of different particle species is recently measured in $Pb-Pb$ collisions by the ALICE experiment at $\sqrt{s}=7 $TeV. This motivates the use of various bosons and baryons measured at lower center-of-mass energies in comparing their ratios to the hadron resonance (HRG) gas model and PYTHIA event generator. It is found that the particle-to-antiparticle ratios are perfectly reproduce by means of HRG and PYTHIA at RHIC and LHC energies. The kaon-to-pion and proton-to-pion ratios are entirely overestimated by the HRG model. The PYTHIA event generator obviously underestimates the kaon-to-pion ratio and simultaneously reproduces the proton-to-pion ratio, almost perfectly, especially at LHC energy. While matter-to-antimatter and non-strange abundances are partly in line with predictions from the HRG model, it is found in the ALICE experiment that the measured baryon ratios are suppressed by a factor of $\sim1.5$. The strange abundances are overestimated in the HRG model.