Oleksii Ivanytskyi (IFT)

Revisiting the Polyakov Loop Nambu-Jona-Lasinio model at finite baryonic density

Phenomenological confinement of quarks within effective approaches is an important ingredient of modeling the equation of state of strongly interacting matter. Coupling quarks to the Polyakov loop, which is an exact order parameter in the pure gauge case, serves as an efficient mechanism for such phenomenological confinement at finite temperatures. I present the Polyakov Loop coupled Nambu-Jona-Lasinio model revisited in order to maintain the Polyakov loop dynamics at vanishing temperature, which is the most interesting for astrophysical applications. This is done by re-examing potential for the deconfinement order parameter at finite baryonic densities. Secondly, and the most important, I explicitly demonstrated that naive modification of this potential at any temperature is formally equivalent to assigning a baryonic charge to gluons. The developed general formulation of the present model is free of the discussed defect and, on the other hand, can be justified within the density functional approach. The Polyakov loop potential is normalized to asymptotic of the QCD equation of state given by the O(α2s) perturbative results. I also demonstrate that incorporation of the Polyakov loop dynamics to the present model sizably stiffens the quark matter equation of state giving a positive feedback to the problem of existence of heavy compact stars with quark cores.