Magnetic susceptibility in QCD

TL;DR

This paper derives a closed-form expression for magnetic susceptibility in the deconfined phase of QCD, highlighting its paramagnetic nature and agreement with lattice data, with implications for experimental measurements.

Contribution

It introduces a new generalized formula for magnetic susceptibility in nonzero magnetic fields applicable to experiments and lattice simulations.

Findings

Magnetic susceptibility increases with temperature.

The derived formula agrees well with lattice data.

The effect is predominantly paramagnetic.

Abstract

Magnetic susceptibility in the deconfined phase of QCD is calculated in a closed form using a recent general expression for the quark gas pressure in magnetic field. Quark selfenergies are entering the result via Polyakov line factors and ensure the total paramagnetic effect, increasing with temperature. A generalized form of magnetic susceptibility in nonzero magnetic field suitable for experimental and lattice measurements is derived, showing a good agreement with available lattice data.