Phase structure of magnetized quark matter at imaginary chemical potential

Abstract

We investigate the phase structure of magnetized quark matter within a nonlocal SU(2) Polyakov-Nambu-Jona-Lasinio model. Our work focuses on the interplay between temperature and imaginary chemical potential in the presence of an external uniform magnetic field, with emphasis on the deconfinement and Roberge-Weiss transitions. We analyze the dependence of the relevant critical temperatures on the external field, and we explore the sensitivity of the phase structure to different Polyakov loop effective potentials. Our results show qualitative agreement with lattice QCD findings, reproducing inverse magnetic catalysis in the chiral sector and a decreasing behavior of the Roberge-Weiss transition temperature with increasing magnetic field.