Deconfinement and chiral phase transitions in quark matter with chiral imbalance

F.X. Azeredo

In this work, we explore the dynamics of phase transitions, such as the chiral and deconfinement transitions, in the quark matter influenced by chiral imbalance. This imbalance measures the difference between right-handed and left-handed quarks in the system, being related to an intrinsic property of the particles called chirality. The study of the effects of this chiral imbalance in a medium can be incorporated into the grand canonical ensemble by introducing a chiral chemical potential, μ5. To conduct this study, the effective quark model in the mean-field approximation, known in the literature as the Polyakov–Nambu–Jona-Lasinio (PNJL) model, was used, which includes important properties of Quantum Chromodynamics (QCD), namely the confinement and the chiral symmetry breaking. A new parametrization of the Polyakov loop potential, which depends on both temperature and chiral chemical potential, was proposed. This parametrization was combined with a regularization scheme known in the literature as “Medium Separation Scheme (MSS)”, which separates the medium finite contributions from the vacuum divergent integrals. Consequently, we have demonstrated that the MSS better describes the medium effects in quark matter compared to another scheme frequently used in the literature, the “Traditional Regularization Scheme (TRS)”. Finally, the main motivation is to show that our results align with lattice QCD predictions, the most powerful non-perturbative approach to QCD, which predicts that the pseudocritical temperatures for the chiraland deconfinement transitions increase with μ5. Using the MSS, we successfully reproduced this behavior. Additionally, an analysis of the order parameters of the system and various thermodynamic quantities was performed, comparing the results of TRS and MSS schemes.