Dark symmetry implication for right-handed neutrinos

We argue that the long-standing issues of neutrino mass and dark matter can be manifestly solved in a dark gauge symmetry U(1)D that transforms nontrivially only for three right-handed neutrinos nu 1;2;3R-the counterparts of known left-handed neutrinos. This theory assigns the nu 1;2;3R dark charge to be D = 0, -1, and +1, respectively, in order for anomaly cancelation. Additionally, it imposes an inert Higgs doublet eta and two Higgs singlets xi; phi with dark charge D = +1, -1, and +2, respectively. That said, the dark symmetry is broken by phi (by two units) down to a dark parity PD = (-1)D, for which nu 2;3R and eta,xi are odd, whereas all other fields are even due to D = 0. The lightest of these odd fields is stabilized by PD, which is responsible for dark matter. Neutrino masses are generated by a scotoseesaw scheme, in which the seesaw part is mediated by nu 1R, while the scotogenic part is mediated by nu 2;3R, for which the hierarchy of atmospheric and solar neutrino mass splittings is explained.