One-loop Type II Seesaw Neutrino Model with Stable Dark Matter Candidates

Abstract

Opening up the Weinberg operator at 1-loop level using a scalar triplet, two scalar doublets and one fermion gives rise to T4-2-i one-loop topology. Neutrino masses generated from this topology are always accompanied by the tree level Type II seesaw contribution. In this work, we propose a radiative Majorana neutrino mass model based on this topology where to avoid the tree level Type II seesaw mechanism, we extend the model by a ${G}_{f}=\mathbb{D}_{4}\times Z_{3}\times Z_{5}\times Z_{2}$ flavor symmetry and we promote the fermion inside the loop to three right-handed neutrinos. In this scenario, the tree level Dirac neutrino masses resulted from these right-handed neutrinos is also prevented by the ${G}_{f}$ group. Moreover, in order for T4-2-i topology to fully function, the scalar sector is extended by two flavon fields where after ${G}_{f}$ symmetry breaking, the model accounts successfully for the observed neutrino masses and mixing as well as allows for the existence of stable dark matter (DM) candidates. Indeed, all the particles running in the loop are potential dark matter candidates as their stability is guaranteed by the unbroken discrete group $Z_{2}\in {G}_{f}$.