Transient anomalous charge production in strong-field QCD

TL;DR

This paper studies how strong gauge fields in non-equilibrium two-color QCD can transiently generate significant axial charge density, with analytical and lattice simulation comparisons revealing persistent anomalous charges.

Contribution

It provides the first detailed analysis of early-time axial charge production in out-of-equilibrium strong-field QCD, combining analytical methods with real-time lattice simulations.

Findings

Coherent gauge fields can produce significant axial charge density transiently.

Part of the induced axial charges persist beyond decoherence times.

Analytic and lattice results agree, validating real-time anomaly representations.

Abstract

We investigate axial charge production in two-color QCD out of equilibrium. We compute the real-time evolution starting with spatially homogeneous strong gauge fields, while the fermions are in vacuum. The idealized class of initial conditions is motivated by glasma flux tubes in the context of heavy-ion collisions. We focus on axial charge production at early times, where important aspects of the anomalous dynamics can be derived analytically. This is compared to real-time lattice simulations. Quark production at early times leading to anomalous charge generation is investigated using Wilson fermions. Our results indicate that coherent gauge fields can transiently produce significant amounts of axial charge density, while part of the induced charges persist to be present even well beyond characteristic decoherence times. The comparisons to analytic results provide stringent tests of real-time representations of the axial anomaly on the lattice.