Neutral pion masses within a hot and magnetized medium in a lattice-improved soft-wall AdS/QCD model

Abstract

We investigate chiral phase transitions and the screening masses, pole masses, and thermal widths of neutral pion mesons with finite temperature T and magnetic field B in a lattice-improved AdS/QCD model, which is constructed by fitting the lattice results of the pseudocritical temperatures Tpc(B). Specifically, we find that the chiral condensate σ undergoes a crossover phase transition demonstrating distinct magnetic catalysis and inverse magnetic catalysis effects in very low- and high-temperature regions with fixed finite B, respectively. For the screening masses, we find that the longitudinal component decreases with B at very low and high temperatures and increases with B near Tpc. The transverse component always increases with B at fixed T. However, both the longitudinal and transverse screening masses increase with T at fixed B. Furthermore, we find that the pole mass decreases with the increase of B or T. It is interesting to note that the thermal width shows similar behavior to the longitudinal screening masses in the very-high-temperature region. Published by the American Physical Society 2024