Confinement effects from a PNJL model at zero temperature regime

The Polyakov-Nambu-Jona-Lasinio (PNJL) model is a model that incorporates confinement effects in the Nambu-Jona-Lasinio (NJL) model through the addition of the Polyakov loop (Φ). These effects are studied at finite temperature regime. However, at zero temperature its modified Fermi-Dirac distributions become step functions and Φ disappears from the equations of state (EOS), as well as the Polyakov potential, leading the model to the conventional form of the NJL model. In this work we propose a variation of the PNJL model where all the couplings depend on Φ with the constraint that the interactions vanish at the deconfinement phase where Φ reaches its maximum value and the quarks behave as free particles. In this approach, coupling constants of original PNJL model become now dependent on Φ. As a consequence, all equations of state present a dependence even at zero temperature regime. The thermodynamics of this new model is discussed. (paper)