MESONIC CORRELATION FUNCTIONS AT FINITE TEMPERATURE AND DENSITY IN THE NAMBU–JONA–LASINIO MODEL WITH A POLYAKOV LOOP

Abstract

We investigate the properties of scalar and pseudo-scalar mesons at finite temperature and quark chemical potential in the framework of the Nambu–Jona-Lasinio (NJL) model coupled to the Polyakov loop (PNJL model) with the aim of taking into account features of both chiral symmetry breaking and deconfinement. In the phase of broken chiral symmetry a narrower width for the σ meson is obtained with respect to the NJL case; on the other hand, the pion still behaves as a Goldstone boson.