Helicitogenesis: WIMPy baryogenesis with sterile neutrinos and other realizations

TL;DR

This paper introduces a new baryogenesis mechanism at the TeV scale involving sterile neutrinos, linking dark matter annihilation, neutrino masses, and the matter-antimatter asymmetry in the universe.

Contribution

It proposes a novel helicitogenesis mechanism where helicity asymmetries from sterile neutrinos generated by dark matter annihilation produce the baryon asymmetry, expanding baryogenesis models.

Findings

Mechanism operates at TeV scale with heavy sterile neutrinos.

Connects dark matter annihilation to baryon asymmetry and neutrino masses.

Provides a framework for multiple realizations of helicitogenesis.

Abstract

We propose a mechanism for baryogenesis from particle decays or annihilations that can work at the TeV scale. Some heavy particles annihilate or decay into a heavy sterile neutrino N (with M > 0.5 TeV) and a "light" one \nu (with m << 100 GeV), generating an asymmetry among the two helicity degrees of freedom of \nu. This asymmetry is partially transferred to Standard Model leptons via fast Yukawa interactions and reprocessed into a baryon asymmetry by the electroweak sphalerons. We illustrate this mechanism in a WIMPy baryogenesis model where the helicity asymmetry is generated in the annihilation of dark matter. This model connects the baryon asymmetry, dark matter, and neutrino masses. Moreover it also complements previous studies on general requirements for baryogenesis from dark matter annihilation. Finally we discuss other possible realizations of this helicitogenesis mechanism.