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

We report on the application of a cascade + viscous hydro + cascade model for heavy ion collisions in the RHIC Beam Energy Scan range, \(\sqrt{s_{\rm NN}}=6.3\dots200\) 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 \(\sqrt{s_{\rm NN}}\approx7\) to 39 GeV.