Baryogenesis with QCD Domain Walls

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.