Covariant interacting Hadron-Resonance Gas model

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.

Comments: 15 pages, 13 figures, version as published in PRC