Diamagnetic and paramagnetic phases in low-energy quantum chromodynamics

While it is known that the QCD vacuum in a magnetic background exhibits both diamagnetic and paramagnetic characteristics in the low-energy domain, a systematic investigation of the corresponding phases emerging in the pion-dominated regime is still lacking. Here, within two-flavor chiral perturbation theory, taking into account the pion-pion interaction, we analyze the subtle interplay between zero-and finite-temperature portions in the magnetization and magnetic susceptibility. The dependence of the magnetic susceptibility on temperature and magnetic field strength in the paramagnetic and diamagnetic phase is non-monotonic. Our low-energy analysis complements lattice QCD that is currently operating at higher temperatures and stronger magnetic fields. (C) 2021 The Author. Published by Elsevier B.V.

Automated summary

In this study, researchers analyzed the properties of magnetization and magnetic susceptibility in the pion-dominated regime within two-flavor chiral perturbation theory. They found that the dependence of magnetic susceptibility on temperature and magnetic field strength in the paramagnetic and diamagnetic phase is non-monotonic. This low-energy analysis complements current lattice QCD operating at higher temperatures and stronger magnetic fields.