Baryogenesis via gauge field production from a relaxing Higgs

TL;DR

This paper proposes a novel baryogenesis mechanism where a relaxing Higgs during inflation produces hypermagnetic helicity, which is then converted into the observed baryon asymmetry via the chiral anomaly at the electroweak phase transition.

Contribution

It introduces a new model linking Higgs dynamics during inflation to baryon asymmetry through hypermagnetic helicity production and conversion.

Findings

The model can reproduce the observed baryon asymmetry.

Conditions for helicity conservation during evolution are discussed.

A simple realization of the mechanism is proposed.

Abstract

We show that the baryon asymmetry of the universe can be explained in models where the Higgs couples to the Chern-Simons term of the hypercharge group and is away from the late-time minimum of its potential during inflation. The Higgs then relaxes toward this minimum once inflation ends which leads to the production of (hyper)magnetic helicity. We discuss the conditions under which this helicity can be approximately conserved during its joint evolution with the thermal plasma. At the electroweak phase transition the helicity is then converted into a baryon asymmetry by virtue of the chiral anomaly in the standard model. We propose a simple model which realizes this mechanism and show that the observed baryon asymmetry of the universe can be reproduced.