QCD Thermodynamics and Magnetization in Nonzero Magnetic Field

Abstract

In nonzero magnetic field, the magnetic properties and thermodynamics of the quantum-chromodynamic (QCD) matter are studied in the hadron resonance gas and the Polyakov linear-sigma models and compared with recent lattice calculations. Both models are fairly suited to describe the degrees of freedom in the hadronic phase. The partonic ones are only accessible by the second model. It is found that the QCD matter has paramagnetic properties, which monotonically depend on the temperature and are not affected by the hadron-quark phase transition. Furthermore, raising the magnetic field strength increases the thermodynamic quantities, especially in the hadronic phase, but reduces the critical temperature, that is, inverse magnetic catalysis.