Magnetization of the QCD vacuum at large fields

TL;DR

This paper investigates the behavior of the QCD vacuum under extremely strong magnetic fields, demonstrating that its magnetization can be accurately described using perturbative QCD and calculating the leading order response.

Contribution

It provides a perturbative calculation of the QCD vacuum magnetization at large magnetic fields, showing the leading order is proportional to B log B and that two-loop corrections vanish.

Findings

Magnetization proportional to B log B at leading order

Two-loop perturbative correction vanishes

QCD vacuum response described by perturbative methods at large fields

Abstract

The response of the QCD vacuum to very large static external magnetic fields (q B >> Lambda_QCD^2) is studied. In this regime, the magnetization of the QCD vacuum is naturally described via perturbative QCD. Combining pQCD and the Schwinger proper time formalism, we calculate the magnetization of the QCD vacuum due to a strong magnetic field at leading order (one-loop) to be proportional to B log B. We show that the leading perturbative correction (two-loop) vanishes.