Relaxation time ansatz and bulk viscosity of hadron matter
The bulk viscosity is calculated for hadron matter produced in heavy-ion collisions, being described in the relaxation-time approximation within the relativistic mean-field-based model with scaled hadron masses and couplings. We show how different approximations used in the literature affect the result. Numerical evaluations of the bulk viscosity with three considered ansatze deviate not much from each other confirming earlier results.