English

Low-scale Leptogenesis with Minimal Lepton Flavour Violation

High Energy Physics - Phenomenology 2019-06-19 v3

Abstract

We analyse the feasibility of low-scale leptogenesis where the inverse seesaw (ISS) and linear seesaw (LSS) terms are not simultaneously present. In order to generate the necessary mass splittings, we adopt a Minimal Lepton Flavour Violation (MLFV) hypothesis where a sterile neutrino mass degeneracy is broken by flavour effects. We find that resonant leptogenesis is feasible in both scenarios. However, because of a flavour alignment issue, MLFV-ISS leptogenesis succeeds only with a highly tuned choice of Majorana masses. For MLFV-LSS, on the other hand, a large portion of parameter space is able to generate sufficient asymmetry. In both scenarios we find that the lightest neutrino mass must be of order 102 eV10^{-2}\text{ eV} or below for successful leptogenesis. We briefly explore implications for low-energy flavour violation experiments, in particular μeγ\mu \rightarrow e\,\gamma. We find that the future MEG-II experiment, while sensitive to MLFV in our setup, will not be sensitive to the specific regions required for resonant leptogenesis.

Keywords

Cite

@article{arxiv.1812.11964,
  title  = {Low-scale Leptogenesis with Minimal Lepton Flavour Violation},
  author = {Matthew J. Dolan and Tomasz P. Dutka and Raymond R. Volkas},
  journal= {arXiv preprint arXiv:1812.11964},
  year   = {2019}
}

Comments

60 pages, 20 figures; v2: Added discussion and figures on the contribution of coherent sterile neutrino oscillations to asymmetry generation; other, minor changes and added references. Conclusions unchanged. Matches version to be published by PRD

R2 v1 2026-06-23T07:00:14.933Z