Hadron resonance gas with repulsive mean field interaction: Thermodynamics and transport properties

We discuss the interacting hadron resonance gas model to describe the thermodynamics of hadronic matter. While the attractive interaction between hadrons is taken care of by including all the resonances with zero width, the repulsive interactions between them are described by a density-dependent mean field potential. The bulk thermodynamic quantities are confronted with the lattice quantum chromodynamics simulation results at zero as well as at finite baryon chemical potential. We further estimate the shear and bulk viscosity coefficients of hot and dense hadronic matter within the ambit of this interacting hadron resonance gas model.

Figure 1

Scaled pressure (left panel) and the interaction measure (right panel) in the RMFHRG and ideal HRG for $\mu =0$. The lattice data are taken from Ref. [8].

Figure 2

Scaled pressure (left panel) and the interaction measure (right panel) in the RMFHRG model at finite baryon chemical potential. The lattice data are taken from Ref. [8].

Figure 3

Speed of sound in the RMFHRG model at finite baryon density. The lattice data are taken from Ref. [8].

Figure 4

The left panel shows the shear viscosity to entropy density ratio estimated within the RMFHRG and compared with other model estimations. These figures correspond to $\mu =0$. The right panel shows $\eta /s$ at two different baryon chemical potentials.

Figure 5

The left panel shows the bulk viscosity to entropy density ratio estimated within the RMFHRG and compared with other model estimations. These results are for $\mu =0$. The right panel shows $\zeta /s$ at two different baryon chemical potentials.

Figure 6

Viscosity coefficients along the freeze-out curve. The freeze-out parametrization is taken from Ref. [114].