# Neutrino Masses from Planck-Scale Lepton Number Breaking

Ibarra, Alejandro (Physik-Department, Technische Universität München, James-Franck-Straße, 85748 Garching, Germany) (School of Physics, Korea Institute for Advanced Study, Seoul 02455, South Korea) ; Strobl, Patrick (Physik-Department, Technische Universität München, James-Franck-Straße, 85748 Garching, Germany) ; Toma, Takashi (Physik-Department, Technische Universität München, James-Franck-Straße, 85748 Garching, Germany)

28 February 2019

Abstract: We consider an extension of the standard model by right-handed neutrinos and we argue that, under plausible assumptions, a neutrino mass of $O\left(0.1\right)\text{}\text{}\mathrm{eV}$ is naturally generated by the breaking of the lepton number at the Planck scale, possibly by gravitational effects, without the necessity of introducing new mass scales in the model. Some implications of this framework are also briefly discussed.

Published in: Physical Review Letters 122 (2019)