Chiral symmetry restoration and deconfinement in the contact interaction model of quarks with parallel electric and magnetic fields

Abstract

We study the impact of steady, homogeneous, and external parallel electric and magnetic field strengths ( ) on the chiral symmetry breaking-restoration and confinement-deconfinement phase transition. We also sketch the phase diagram of quantum chromodynamics (QCD) at a finite temperature T and in the presence of background fields. The unified formalism for this study is based on the Schwinger-Dyson equations, symmetry preserving vector-vector contact interaction model of quarks, and an optimal time regularization scheme. At , in the purely magnetic case (i.e., ), we observe the well-known magnetic catalysis effect. However, in a pure electric field background ( ), the electric field tends to restore the chiral symmetry and deconfinement above the pseudo-critical electric field . In the presence of both and , we determine the magnetic catalysis effect in the particular region where dominates over , whereas we observe the chiral inhibition (or electric chiral rotation) effect when overshadows eB. At finite T, in the pure electric field case, the phenomenon of inverse electric catalysis appears to exist in the proposed model. Conversely, for a pure magnetic field background, we observe the magnetic catalysis effect in the mean-field approximation and inverse magnetic catalysis with -dependent coupling. The combined effects of and on the pseudo-critical yields an inverse electromagnetic catalysis, with and without an -dependent effective coupling of the model. The findings of this study agree well with the already predicted results obtained via lattice simulations and other reliable effective models of QCD.