van der Waals hadron resonance gas and QCD phase diagram

TL;DR

This study uses a van der Waals inspired equation of state to analyze the thermodynamic properties of hadron resonance gas, shedding light on the QCD phase diagram and the potential location of the critical point.

Contribution

It introduces a VDW-like EoS for hadron gas, calibrated with lattice QCD data, to explore phase transitions and the critical point in the QCD phase diagram.

Findings

Identification of first order phase transition and crossover regions.

Estimation of the critical point location consistent with recent studies.

Temperature and chemical potential dependence of $s /T^3$ and $\\eta/ s$ analyzed.

Abstract

Taking into account the recently developed van der Waals (VDW) like equation of state (EoS) for grand canonical ensemble of fermions, the temperature dependent profiles of normalized entropy density ($s /T^3$) and the ratio of shear viscosity and entropy density ($\eta/ s$) for hadron resonance gas have been evaluated. The VDW parameters, corresponding to interactions between (anti)baryons, have been obtained by contrasting lattice EoS for QCD matter at finite chemical potentials ($\mu_{B}$) and for $T \le$ 160 MeV. The temperature and chemical potential dependent study of $s /T^3$ and $\eta /s$ for hadron gas, by signalling onsets of first order phase transition and crossover in the hadronic phase of QCD matter, helps in understanding the QCD phase diagram in the ($T, \mu_{B}$) - plane. An estimation of probable location of critical point matches predictions from other recent studies.