A hadron resonance gas model including all known particles and resonances with masses m<2GeV and an exponentially rising density of Hagedorn states for m>2GeV is used to obtain an upper bound on the shear viscosity to entropy density ratio, η/s≈1/(4π), of hadronic matter near Tc. We found a large trace anomaly and small speed of sound near Tc, which agree well with recent lattice calculations. We comment on the bulk viscosity to entropy density ratio close to Tc.
ASJC Scopus subject areas
- Physics and Astronomy(all)