Magnetic susceptibility at zero and nonzero chemical potential in QCD and QED

TL;DR

This paper calculates the magnetic susceptibility of quark matter in QCD at various chemical potentials and magnetic fields, revealing temperature-dependent behaviors and oscillations, with comparisons to lattice data.

Contribution

It provides a closed-form calculation of magnetic susceptibility in QCD for arbitrary chemical potential, highlighting new temperature and magnetic field effects.

Findings

Susceptibility depends strongly on temperature for small chemical potential.

Oscillations in susceptibility occur at high magnetic fields, similar to de Haas-van Alphen effect.

Results agree with existing lattice data.

Abstract

Magnetic susceptibility of the quark matter in QCD is calculated in a closed form for an arbitrary chemical potential \mu. For small \mu, \mu<<T, eB << T^2, a strong dependence on temperature T is found due to Polyakov line factors. In the opposite case of small T, eB > T^2, the oscillations as functions of eB occur, characteristic of the de Haas-van Alphen effect. Results are compared with available lattice data.