Estimating $\eta /s$ of QCD matter at high baryon densities

Abstract

We report on the application of a cascade + viscous hydro + cascade model for heavy ion collisions in the RHIC Beam Energy Scan range, $\sqrt{s_{\mathrm{NN}}}=6.3\dots 200$ GeV. By constraining model parameters to reproduce the data we find that the effective(average) value of the shear viscosity over entropy density ratio $\eta /s$ decreases from 0.2 to 0.08 when collision energy grows from $\sqrt{s_{\mathrm{NN}}}\approx 7$ to 39 GeV.

Comments: 4 pages, proceedings of the Strangeness in Quark Matter 2015, Dubna, July 6-11, 2015