Baryogenesis in a CP invariant theory

TL;DR

This paper proposes a novel baryogenesis mechanism in a CP invariant theory, where tunneling processes involving the inflaton generate the observed matter-antimatter asymmetry without spontaneous CP violation.

Contribution

It introduces a model where CP violation arises from tunneling processes in a CP invariant setup, with the inflaton field mediating the baryogenesis.

Findings

Tunneling processes can generate CP violation in a CP invariant universe.

The inflaton field can carry the CP violating phase across the universe.

The model successfully explains the matter-antimatter asymmetry without spontaneous CP breaking.

Abstract

We consider baryogenesis in a model which has a CP invariant Lagrangian, CP invariant initial conditions and does not spontaneously break CP at any of the minima. We utilize the fact that tunneling processes between CP invariant minima can break CP to implement baryogenesis. CP invariance requires the presence of two tunneling processes with opposite CP breaking phases and equal probability of occurring. In order for the entire visible universe to see the same CP violating phase, we consider a model where the field doing the tunneling is the inflaton.