Field-strength correlators for QCD in a magnetic background

TL;DR

This study uses lattice Monte Carlo simulations to explore how an external magnetic field affects the gauge-invariant two-point correlation functions and gluon condensate in two-flavor QCD, revealing anisotropies and increased condensate strength.

Contribution

It provides the first lattice-based evidence of anisotropies and gluon condensate enhancement in QCD under a magnetic background, advancing understanding of nonperturbative effects.

Findings

Anisotropies emerge in gauge-field correlators due to magnetic field

Gluon condensate increases with magnetic field strength

Results suggest magnetic fields influence nonperturbative QCD dynamics

Abstract

We present the results of an exploratory study (by means of Monte Carlo simulations on the lattice) of the properties of the gauge-invariant two-point correlation functions of the gauge-field strengths for $N_f=2$ QCD at zero temperature and in the presence of a magnetic background field: the analysis provides evidence for the emergence of anisotropies in the nonperturbative part of the correlators and for an increase of the gluon condensate as a function of the external magnetic field.