Scalar triplet leptogenesis without right-handed neutrino decoupling

TL;DR

This paper explores scalar triplet leptogenesis within type-II seesaw models, considering the combined effects of scalar triplet and right-handed neutrino decays, identifying three model classes with distinct leptogenesis outcomes.

Contribution

It introduces a framework analyzing leptogenesis with both scalar triplet and right-handed neutrino decays, classifying models based on parameter hierarchies.

Findings

Three classes of models with different leptogenesis mechanisms

Conditions under which right-handed neutrino decays influence asymmetry

Implications for model building in neutrino mass generation

Abstract

We discuss leptogenesis in the context of type-II seesaw in the case in which in addition to the scalar electroweak triplet decays the lepton asymmetry is also induced by right-handed neutrino decays (mild hierarchical scenarios). We show that within this setup, depending on the relative sizes of the relevant parameters, one can identify three classes of generic models, each one with its own consequences for leptogenesis.