Baryogenesis with QCD Domain Walls

TL;DR

This paper introduces a novel QCD-scale baryogenesis mechanism involving domain walls with fractional baryon charges, linking baryon asymmetry and dark matter to metastable vacuum regions during the QCD phase transition.

Contribution

It proposes a new baryosymmetric baryogenesis process at the QCD scale based on domain walls and metastable vacua, connecting baryon asymmetry and dark matter.

Findings

Domain walls acquire fractional baryon charges.

Metastable vacuum regions may contribute to dark matter.

Baryon asymmetry linked to non-zero theta angle near QCD transition.

Abstract

We propose a new baryosymmetric mechanism for baryogenesis which takes place at the QCD scale and is based on the existence of domain walls separating the metastable vacua from the lowest energy vacuum. The walls acquire fractional negative and positive baryon charges, while the observed baryon asymmetry is due to a non-zero value of the $ \theta $ angle at the temperatures near the QCD chiral phase transition. The regions of metastable vacuum bounded by walls carry a negative baryon charge and may contribute a significant fraction of the dark matter of the Universe.