Hydrodynamics with a chiral hadronic equation of state including quark degrees of freedom

Abstract

We investigate the influence of a deconfinement phase transition on the dynamics of hot and dense nuclear matter. We apply a hybrid model where an intermediate hydrodynamics stage is employed for the the hot and dense stage of a system created in head-on collisions of Pb+Pb/Au+Au at beam energies from $2-160A$GeV. The initial and final interactions are performed by a microscopic transport approach (UrQMD). An equation of state that incorporates a critical end point (CEP) in line with lattice data is used. It follows from coupling the Polyakov loop (as an order parameter for deconfinement) to a chiral hadronic $SU(3{)}_f$ model. In this configuration the EoS describes chiral restoration as well as the deconfinemt phase transition. We compare the results obtained in this approach to results from a non interacting hadron resonance gas, focussing on observables deemed to be sensitive to the phase transition to the quark gluon plasma.

Comments: Published version