Dr. Yuriy Karpenko (INFN and University of Florence),

### Viscous hydro + cascade modeling of heavy ion collisions at \sqrt{s_{NN}} = 7.7-200 GeV

State-of-the-art 3D viscous hybrid model is applied to heavy ion collisions at RHIC Beam Energy Scan (BES) energy range \sqrt{s}=7.7...200 GeV. The model employs the hadron transport approach UrQMD for the early and late non-equilibrium stages of the reaction, and 3+1 dimensional viscous hydrodynamics for the hot and dense quark-gluon plasma stage. It includes the equation of motion for finite baryon number, and employs an equation of state with finite net-baryon density to allow for calculations in a large range of beam energies. The parameter space of the model is explored, and constrained by comparison with the experimental data for bulk observables from SPS and the phase I BES at RHIC. The favored parameter values depend on energy, but allow to extract the effective value of the shear viscosity coefficient over entropy density ratio \eta/s in the fluid phase for the whole energy region under investigation. The estimated value of effective \eta/s increases with decreasing collision energy, which may indicate that \eta/s of the quark-gluon plasma increases with increasing baryochemical potential \mu_B.