New scenarios for hard-core interactions in a hadron resonance gas

TL;DR

This paper explores different scenarios of hard-core interactions in a hadron resonance gas, analyzing their effects on thermodynamics and particle ratios, with implications for heavy-ion collision experiments.

Contribution

It introduces new scenarios for baryon interactions in a hadron resonance gas and studies their effects on thermodynamic properties and particle yield ratios.

Findings

Identifies nontrivial effects at temperatures 150-200 MeV.

Fits hadron yield data from Pb+Pb collisions at 2.76 TeV.

Analyzes impact of different interaction assumptions on particle ratios.

Abstract

The equation of state of a baryon-symmetric hadronic matter with hard-sphere interactions is studied. It is assumed that mesons are point-like, but baryons and antibaryons have the same hard-core radius rB. Three possibilities are considered: 1) the baryon-baryon and antibaryon-baryon interactions are the same; 2) baryons do not interact with antibaryons; 3) the baryon-antibaryon and meson-(anti)baryon interactions are negligible. By choosing the parameter rB=0.3-0.6 fm, we calculate the nucleon to pion ratio as a function of temperature and perform the fit of hadron yields measured in central Pb+Pb collisions at the bombarding energy Ecm=2.76 TeV per nucleon pair. New nontrivial effects in the interacting hadron resonance gas at temperatures 150-200 MeV are found.