Diffusion and shear viscosity coefficients of hot isospin asymmetric strange hadronic matter using a chiral SU(3) model

Abstract

We study the diffusion and shear viscosity coefficients of hot isospin asymmetric strange hadronic matter. The effects due to the baryon density, isospin, strangeness, and temperature on the nucleons and hyperons are studied within a chiral SU(3) model. The medium modifications of the baryons arise due to interactions with the mean scalar and vector fields within the model. The thermodynamic and transport properties are studied in the hot strange hadronic matter. The diffusion matrix associated with the multiple charges (baryon number, isospin, and strangeness), as well as the coefficient of shear viscosity, are computed from the Boltzmann equation using first-order Chapman--Enskog expansion within the relaxation time approximation. There are observed to be significant effects from the isospin asymmetry as well as the strangeness of the medium on the diffusion coefficients. The coefficient of shear viscosity, $η$ is observed to have a large enhancement in the presence of finite strangeness in the medium due to additional contributions from the hyperons. The effects due to isospin asymmetry on the shear viscosity coefficient is however observed to be marginal both in nuclear and hyperonic matter. The present study can be relevant for the experimental observables of asymmetric relativistic heavy-ion collisions, e.g., in the compressed baryonic matter (CBM) experiment at the FAIR facility at GSI as well as in the future J-PARC-HI program.