Low-scale leptogenesis in the scotogenic model: spectator processes and benchmark points

TL;DR

This paper investigates low-scale leptogenesis in the scotogenic model, emphasizing spectator processes and benchmark points, and demonstrates the viability of leptogenesis at TeV-scale sterile neutrino masses with potential observable flavor violation.

Contribution

It analyzes how spectator processes enable successful leptogenesis at TeV-scale masses in the scotogenic model, including for different initial neutrino abundances.

Findings

Leptogenesis can occur successfully at TeV-scale sterile neutrino masses.

Spectator processes are crucial for suppressing washouts in the model.

Large Yukawa couplings can lead to observable charged lepton flavor violation.

Abstract

We study leptogenesis from the decay of the lightest sterile neutrino in the scotogenic model with a scalar dark matter candidate. Our analysis focuses on the possible exponential suppression of washouts for sizable values of the inert Higgs mass and the crucial role of some spectator processes for this to happen. We show that leptogenesis can be successful for TeV-scale masses of the lightest sterile neutrino for both, thermal and zero, initial abundances of the neutrinos. Moreover, leptogenesis is viable for Yukawa couplings of the heavier sterile neutrinos large enough to yield observable charged lepton flavor violation processes in current and planned experiments.