Shear viscosity of hadronic gas mixtures

We investigate the effects of the baryon chemical potential μ on the shear viscosity coefficient η and the viscosity to entropy density ratio η/s of a pion–nucleon gas mixture. We find that η is an increasing function of T and μ, while the ratio η/s turns to a decreasing function in a wide region of the T–μ plane. In the kinematical region we studied, the smallest value of η/s is about 0.3.