Suppression of thermal vorticity as an indicator of QCD critical point

Abstract

We study the impact of the QCD critical point (CP) on the spin polarization of $\Lambda$-hyperon generated by the thermal vorticity in viscous quark gluon plasma (QGP). The equations of the relativistic causal viscous hydrodynamics have been solved numerically in (3+1) dimensions to evaluate the thermal vorticity. The effects of the CP have been incorporated through the equation of state (EoS) and the scaling behavior of the transport coefficients. A significant reduction in the global polarization has been found as the CP is approached. A drastic change induced by the CP in the rapidity dependence of the spin polarization is observed which can be used as a signature of the CP.