Low-scale leptogenesis with three heavy neutrinos

Asmaa Abada (1) , Giorgio Arcadi , Valerie Domcke , Marco Drewes , Juraj Klaric , Michele Lucente

1 LPT - Laboratoire de Physique Théorique d'Orsay [Orsay]

Leptogenesis induced by the oscillations of GeV-scale neutrinos provides a minimal and testable explanation of the baryon asymmetry of the Universe. In this work we extend previous studies invoking only two heavy neutrinos to the case of three heavy neutrinos. We find qualitatively new behaviour as a result of lepton number violating oscillations and decays, strong flavour effects in the washout and a resonant enhancement due to matter effects. An approximate global $ B-\overline{L} $ symmetry (representing the difference of baryon and a generalised lepton number) can protect the light neutrino masses from large radiative corrections, while simultaneously providing the ingredients for the resonant enhancement of the lepton asymmetry due to thermal contributions to the heavy neutrino dispersion relations. This mechanism is particularly efficient for large heavy neutrino mixing angles near the current experimental limits, a regime in which leptogenesis is not feasible in the minimal scenario with two heavy neutrinos. In this new parameter regime, low-scale leptogenesis is testable by the LHC and other existing experiments.

Mots clés: neutrino: oscillation; flavor: asymmetry; leptogenesis; CERN LHC Coll; lepton number; baryogenesis; thermal; model: kinetic; quantum; parameter space; B-L number; seesaw model; Cosmology of Theories beyond the SM; Neutrino Physics; Thermal Field Theory; CP violation; new physics; neutrino: heavy; neutrino: mass; neutrino: right-handed

Domaines: Physique des Hautes Energies - Phénoménologie [hep-ph]; Physique des Hautes Energies - Expérience [hep-ex]

Asmaa Abada, Giorgio Arcadi, Valerie Domcke, Marco Drewes, Juraj Klaric, et al.. Low-scale leptogenesis with three heavy neutrinos. Journal of High Energy Physics, 2019, 01, pp.164. ⟨10.1007/JHEP01(2019)164⟩. ⟨hal-01921716⟩