Dark matter and observable Lepton Flavour Violation
arXiv:1607.01798 · doi:10.1103/PhysRevD.94.125022
Abstract
Seesaw models with leptonic symmetries allow right-handed (RH) neutrino masses at the electroweak scale, or even lower, at the same time having large Yukawa couplings with the Standard Model leptons, thus yielding observable effects at current or near-future lepton-flavour-violation (LFV) experiments. These models have been previously considered also in connection to low-scale leptogenesis, but the combination of observable LFV and successful leptogenesis has appeared to be difficult to achieve unless the leptonic symmetry is embedded into a larger one. In this paper, instead, we follow a different route and consider a possible connection between large LFV rates and Dark Matter (DM). We present a model in which the same leptonic symmetry responsible for the large Yukawa couplings guarantees the stability of the DM candidate, identified as the lightest of the RH neutrinos. The spontaneous breaking of this symmetry, caused by a Majoron-like field, also provides a mechanism to produce the observed relic density via the decays of the latter. The phenomenological implications of the model are discussed, finding that large LFV rates, observable in the near-future conversion experiments, require the DM mass to be in the keV range. Moreover, the active-neutrino coupling to the Majoron-like scalar field could be probed in future detections of supernova neutrino bursts.
10 pages, 8 figures; extended discussion, version to appear in PRD
References in corpus (14)
- Sterile neutrinos, dark matter, and the pulsar velocities in models with a Higgs singlet
- Dark-matter sterile neutrinos in models with a gauge singlet in the Higgs sector
- Minimal Flavour Seesaw Models
- Flavour Covariant Transport Equations: an Application to Resonant Leptogenesis
- The Poker Face of the Majoron Dark Matter Model: LUX to keV Line
- Thermal production of relativistic Majorana neutrinos: Strong enhancement by multiple soft scattering
- On the hadronic contribution to sterile neutrino production
- Dark Matter and Gauge Coupling Unification in Non-supersymmetric SO(10) Grand Unified Models
- keV Sterile Neutrino Dark Matter from Singlet Scalar Decays: Basic Concepts and Subtle Features
- Revising Limits on Neutrino-Majoron Couplings
- Relic Gravity Waves and 7 keV Dark Matter from a GeV scale inflaton
- Constraints on secret neutrino interactions after Planck
- Electroweak Resonant Leptogenesis in the Singlet Majoron Model
- Corrigendum to "Flavour Covariant Transport Equations: an Application to Resonant Leptogenesis"