Anisotropic transport properties of a hadron resonance gas in a magnetic field
Ashutosh Dash, Subhasis Samanta, Jayanta Dey, Utsab Gangopadhyaya, Sabyasachi Ghosh, Victor Roy
Abstract
An intense transient magnetic field is produced in high energy heavy-ion collisions mostly due to the spectator protons inside the two colliding nuclei. The magnetic field introduces anisotropy in the medium, and hence the isotropic scalar transport coefficients become anisotropic and split into multiple components. Here, we calculate the anisotropic transport coefficients' shear, bulk viscosity, and electrical conductivity, and the thermal diffusion coefficients for a multicomponent hadron resonance gas (HRG) model for a nonzero magnetic field by using the Boltzmann transport equation in a relaxation time approximation (RTA). The anisotropic transport coefficient component along the magnetic field remains unaffected by the magnetic field, while perpendicular dissipation is governed by the interplay of the collisional relaxation time and the magnetic time scale, which is inverse of the cyclotron frequency. We calculate the anisotropic transport coefficients as a function of temperature and magnetic field using the HRG model. The neutral hadrons are unaffected by the Lorentz force and do not contribute to the anisotropic transports, we estimate within the HRG model the relative contribution of isotropic and anisotropic transports as a function of magnetic field and temperature. We also give an estimation of these anisotropic transport coefficients for the hadronic gas at finite baryon chemical potential (${\ensuremath{\mu}}_{B}$).