$\nu$ Electroweak Baryogenesis

TL;DR

This paper explores whether neutrino Yukawa couplings can provide the CP violation needed for electroweak baryogenesis, linking neutrino mass mechanisms with the matter-antimatter asymmetry of the universe.

Contribution

It demonstrates that neutrino Yukawa couplings at the electroweak scale can generate sufficient CP violation for baryogenesis, considering flavor effects and collider testability.

Findings

Flavor effects are crucial for the final asymmetry.

Observed baryon asymmetry can be achieved in some parameter regions.

Active-heavy neutrino mixing could be detectable at colliders.

Abstract

We investigate if the CP violation necessary for successful electroweak baryogenesis may be sourced by the neutrino Yukawa couplings. In particular, we consider an electroweak scale Seesaw realisation with sizeable Yukawas where the new neutrino singlets form (pseudo)-Dirac pairs. We find that flavour effects critically impact the final asymmetry obtained and that, taking them into account, the observed value may be obtained in some regions of the parameter space. This source of CP violation naturally avoids the strong constraints from electric dipole moments and links the origin of the baryon asymmetry of the Universe with the mechanism underlying neutrino masses. Interestingly, the mixing of the active and heavy neutrinos needs to be sizeable and could be probed at the LHC or future collider experiments.