Covariant interacting Hadron-Resonance Gas model

TL;DR

This paper extends the Hadron-Resonance Gas model to include interactions at high chemical potentials using relativistic mean-field theory, aligning with lattice and nuclear data to better understand the phase boundary of strongly interacting matter.

Contribution

It introduces a covariant, thermodynamically consistent interacting HRG model that incorporates baryonic interactions at finite chemical potential, constrained by lattice and nuclear data.

Findings

Reproduces lattice QCD data at zero chemical potential

Aligns with nuclear equation of state at zero temperature and finite chemical potential

Provides insights into the hadronic to partonic phase transition boundary

Abstract

The Hadron-Resonance Gas (HRG) approach - used to model hadronic matter at small baryon potentials $\mu_B$ and finite temperature $T$ - is extended to finite and large chemical potentials by introducing interactions between baryons in line with relativistic mean-field theory defining an interacting HRG (IHRG). Using lattice data for $\mu_B=0$ as well as information on the nuclear equation of state at $T=0$ we constrain the attractive and repulsive interactions of the IHRG such that it reproduces the lattice equation of state at $\mu_B=0$ and the nuclear equation of state at $T=0$ and finite $\mu_B$. The formulated covariant approach is thermodynamically consistent and allows us to provide further information on the phase boundary between hadronic and partonic phases of strongly interacting matter by assuming constant thermodynamic potentials.