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HK: Fachverband Physik der Hadronen und Kerne
HK 20: Heavy Ion Collisions and QCD Phases IV
HK 20.6: Vortrag
Dienstag, 28. März 2017, 15:30–15:45, F 1
Shear viscosity and entropy of a hadron gas — •Jean-Bernard Rose1,2, Dmytro Oliinychenko1,2, Juan Torres-Rincon1, and Hannah Petersen1,2,3 — 1Frankfurt Institute for Advanced studies, Frankfurt am Main, Deutschland — 2Goethe Universität, Frankfurt am Main, Deutschland — 3GSI Helmholzzentrum für Schwerionenforschung, Darmstadt, Deutschland
Microscopic non-equilibrium dynamics are used to calculate the transport coefficients of dense hadronic matter. Specifically, the shear viscosity to entropy density ratio is investigated, its temperature dependence between 75 MeV and 175 MeV is explored, and the effects of non-zero baryon and strange chemical potentials are probed. This is important to constrain the value of shear viscosity over entropy density used in hydrodynamic calculations of heavy ion reactions at RHIC and the LHC. Calculations are initialized using particle densities computed from a thermal model in a hadronic box simulating infinite matter. After an equilibration delay, the shear viscosity is computed using the Green-Kubo formalism. We use the Gibbs formulato get the entropy density and spectral fitting to obtain the equilibrated temperatures and chemical potentials of the system. The results for the entropy and shear viscosity of a massive and massless pion gas are compared to analytic estimates. The shear viscosity to entropy density ratio is found to be significantly lower than found in previous similar calculations, but in qualitative agreement with other calculations using other methods. This will be the starting point for the calculation of more transport coefficients as functions of temperature and chemical potential.