Effect of the anomalous magnetic moment on the chiral transition in a strong magnetic field

The chiral transition and crossover in strong magnetic fields with an anomalous magnetic moment (AMM) are investigated in the two-flavor Nambu-Jona-Lasinio model. The vacuum divergence and nonphysical oscillation are removed by employing a magnetic-field-independent regularization scheme. In addition to the inverse magnetic catalysis effect, the nonzeroAMMwill turn the chiral crossover into a firstorder phase transition. These effects have been clearly demonstrated by the smooth and sharp peaks of the thermal susceptibility and the distinct behavior of the speed of sound. Magnetic catalysis with zero AMM could probably develop into inverse magnetic catalysis with nonzero AMM at both zero and finite chemical potentials.