Axial anomaly and energy dependence of hyperon polarization in Heavy-Ion Collisions

A. Sorin, O. Teryaev

Published 2016-06-27Version 1

We address the issue of energy and charge dependence of global polarization of $\Lambda$ hyperons in peripheral $Au-Au$ collisions recently observed by STAR collaboration at RHIC. We compare the different contributions to the anomalous mechanism relating polarization to vorticity and hydrodynamic helicity in QCD matter. We stress that the suppression of gravitational anomaly related contribution in strongly correlated matter observed in lattice simulations confirms our earlier prediction of rapid decrease of polarization with collision energy. Our mechanism leads to the polarization of $\bar \Lambda$ of the same sign and larger magnitude than $\Lambda$. The energy and charge dependence of polarization is suggested as a sensitive probe of fine details of QCD matter structure.