Effective ℒ5 Lagrangian and masses of Majorana neutrinos

Abstract

Using the fact that neutrinos only participate in weak and gravitational interactions, we explore the possibility of having their masses emerged at the intersection between extended electroweak theory and theory of gravity. We describe how these two seemingly incompatible theories could be embedded in a lepton-number violating 5-dimensional Lagrangian [Formula: see text]. A peculiar feature of this approach is its ability to generate effective Majorana neutrino masses via the spontaneous symmetry breaking (SSB) of Grand Unified Theory (GUT), [Formula: see text] and 4[Formula: see text] symmetric matrix of gravitational couplings. Within the purview of this theoretical framework, we obtain values for the effective Majorana mass [Formula: see text][Formula: see text]meV, and the Majorana neutrino masses [Formula: see text][Formula: see text]meV, [Formula: see text][Formula: see text]meV, [Formula: see text][Formula: see text]meV, [Formula: see text][Formula: see text]meV and [Formula: see text][Formula: see text]eV. Our results are in good agreement with both experimental and cosmological data.