Abstract: The bulk viscosity ($\zeta$) of the hadronic medium has been estimated within the ambit of the Hadron Resonance Gas (HRG) model including the Hagedorn density of states. The HRG thermodynamics within a grand canonical ensemble provides the mean hadron number as well as its fluctuation. The fluctuation in the chemical composition of the hadronic medium in the grand canonical ensemble can result in non-zero divergence of the hadronic fluid flow velocity, allowing us to estimate the $\zeta$ of the hadronic matter upto a relaxation time. We study t...
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Topics: 
Particle physics
Nuclear physics
Thermodynamics