QCD preheating: New frontier of baryogenesis

Abstract

We find that QCD can create the cosmological matter abundance via out-of-equilibrium processes during the QCD phase transition, that is what we call the QCD preheating, where the dynamic transition of the QCD vacuum characterized by the quark condensate takes place instantaneously. This mechanism works when the Universe undergoes subsequent supercooled QCD transition. We also find that the QCD preheating can work to create the baryon asymmetry of the Universe if there is the new physics communicated with QCD. These are new pictures of the thermal history around the QCD-phase transition epoch, and thus the dynamic aspect of the QCD vacuum opens a new frontier to explore low-scale matter generation such as baryogenesis. Pursuing the QCD reheating era would also help deeply understanding the subatomic-scale physics in the thermal history of the Universe.