Implications of Flavor Dynamics for Fermion Triplet Leptogenesis

TL;DR

This paper explores how flavor effects influence leptogenesis via Majorana triplet decays, showing that these effects can significantly enhance the generated asymmetry and impact TeV-scale triplet phenomenology.

Contribution

It provides a detailed analysis of flavor effects in triplet leptogenesis, highlighting scenarios where these effects are crucial for asymmetry generation and potential collider signatures.

Findings

Flavor effects can enhance the $B-L$ asymmetry by over an order of magnitude.

Asymmetry production above the TeV scale can survive triplet washouts.

Collider observables can help distinguish different leptogenesis scenarios.

Abstract

We analyze the importance of flavor effects in models in which leptogenesis proceeds via the decay of Majorana electroweak triplets. We find that depending on the relative strengths of gauge and Yukawa reactions the $B-L$ asymmetry can be sizably enhanced, exceeding in some cases an order of magnitude level. We also discuss the impact that such effects can have for TeV-scale triplets showing that as long as the $B-L$ asymmetry is produced by the dynamics of the lightest such triplet they are negligible, but open the possibility for scenarios in which the asymmetry is generated above the TeV scale by heavier states, possibly surviving the TeV triplet related washouts. We investigate these cases and show how they can be disentangled at the LHC by using Majorana triplet collider observables and, in the case of minimal type III see-saw models even through lepton flavor violation observables.