Termodinâmica e transições de fase existentes na matéria de quarks com desbalanceamento quiral

Abstract

In this dissertation, we have used effective models, such as the Nambu-Jona-Lasinio (NJL) and the Polyakov–Nambu–Jona-Lasinio (PNJL) to describe and study the Quantum Chromodynamics (QCD) phase diagram with chiral imbalance. We first studied and reproduced results already established in the literature in the context of the NJL model, discussing the effects of this imbalance on the order parameters of the model, and then extended the same study to the PNJL model. In addition, for both models, we studied the effects of chiral imbalance on thermodynamic quantities and, finally, on the phase transitions of the phase diagrams. In this context, different regularization schemes were used, based on the separation of medium effects from the divergent integrals, which appear in the vacuum of the NJL and PNJL models, when the temperature and chiral imbalance are zero. Finally, we carried out a more in-depth study of the PNJL model, which considers the property of confinement together with the breaking of chiral symmetry. We showed that, by regularizing only the vacuum contribution and including a dependence on µ5 in the pure gluon sector, we obtain a better and consequently closer description of the chiral transition and deconfinement compared to the lattice QCD simulations results.