Study of polarization in relativistic nuclear collisions

We present a calculation of the global polarization of hyperons in relativistic Au–Au collisions at RHIC Beam Energy Scan range √ sNN = 7.7−200 GeV with a 3 + 1-dimensional cascade + viscous hydro model, UrQMD + vHLLE. Within this model, the mean polarization of in the out-of-plane direction is predicted to decrease rapidly with collision energy from a top value of about 2% at the lowest energy examined. We explore the connection between the polarization signal and thermal vorticity and estimate the feed-down contribution to polarization due to the decay of higher mass hyperons.