Hypermagnetic Baryogenesis

TL;DR

This paper proposes a novel baryogenesis mechanism involving hypermagnetic helicity and CPT violation, which can generate the observed baryon asymmetry without being washed out by sphalerons, across a wide range of energy scales.

Contribution

It introduces a new scenario for baryogenesis based on hypermagnetic helicity and CPT violation, providing a potential explanation for the Universe's baryon asymmetry.

Findings

Hypermagnetic helicity can induce CPT violation leading to baryon asymmetry.

The mechanism works across a wide mass scale from TeV to Planck.

Sufficient magnetic field amplitudes can produce observed baryon asymmetry.

Abstract

We study a new scenario for baryogenesis due to the spontaneous breaking of the $CPT$ invariance through the interaction between a baryon current and a hypermagnetic helicity. The hypermagnetic helicity (Chern-Simons number) of $U(1)_Y$ provides a $CPT$ violation background for the generation of baryons via sphaleron processes, which protects these baryons from the sphaleron wash-out effect in thermal equilibrium. It is shown that if the present amplitude of the resultant magnetic fields are sufficiently large, for a wide range mass scale (from TeV to the Planck scale), the observational magnitude of the baryon asymmetry of the Universe can be realized.