High-scale leptogenesis with three-loop neutrino mass generation and dark matter

TL;DR

This paper presents a model linking high-scale leptogenesis, three-loop neutrino mass generation, and dark matter, extending the Standard Model with new scalars and fermions to explain matter-antimatter asymmetry and neutrino masses.

Contribution

It introduces a unified framework connecting leptogenesis, neutrino masses, and dark matter via a three-loop mechanism and new scalar and fermion fields.

Findings

Successful generation of lepton asymmetry through scalar decays.

Neutrino masses generated at three-loop level.

Identification of a stable fermion as dark matter candidate.

Abstract

We demonstrate a common origin for high-scale leptogenesis and three-loop neutrino mass generation. Specifically we extend the standard model by two real singlet scalars, two singly charged scalars carrying different lepton numbers and two or more singlet fermions with Majorana masses. Our model respects a softly broken lepton number and an exactly conserved $Z_2^{}$ discrete symmetry. Through the lepton-number-violating decays of the real scalars and then the lepton-number-conserving decays of the charged scalars, we can obtain a lepton asymmetry stored in the standard model leptons. This lepton asymmetry can be partially converted to a baryon asymmetry by the sphaleron processes. The interactions for this leptogenesis can also result in a three-loop diagram to generate the neutrino masses. The lightest singlet fermion can keep stable to serve as a dark matter particle.