Inverse Magnetic Catalysis within a Confining Contact Interaction Model for Quarks
We evaluate the impact of an external magnetic field on the chiral symmetry and confinement-deconfinement transition temperatures by using a vector-vector contact interaction model for quarks regularized so as to include an explicit confining scale in the corresponding gap equation. Exploring the evolution of the chiral condensate and the confining scale with temperature T and magnetic field strength eB (e represents the fundamental electric charge), we determine the pseudo-critical temperatures for the chiral (Tχc) and deconfinement (Tcc) transitions from their inflection points, respectively. By construction, Tχc=Tcc in the chiral limit. Within a mean field approximation, we observe the magnetic catalysis phenomenon, characterized by a rising behavior of Tχc and Tcc with growing eB. Considering a lattice inspired running coupling which monotonically decreases with eB, inverse magnetic catalysis takes place in our model. Our findings are also in agreement with predictions derived from effective models of strong interactions.