Masses of neutrinos in unification gauge theories and neutrino-antineutrino oscillations

Abstract

We discuss two types of neutrino oscillation: (I) the ${\ensuremath{\nu}}_{e}\ensuremath{\rightarrow}{\ensuremath{\nu}}_{\ensuremath{\mu}}$ type of oscillations and (II) the $\ensuremath{\nu}\ensuremath{\rightarrow}{\ensuremath{\nu}}^{c}$ type of neutrino-antineutrino oscillations. To connect the oscillation phenomenology with mass differences of the neutrinos, we discuss possible neutrino mass patterns in a general form including the Dirac mass and the Majorana mass, when there are both left- and right-handed neutrinos. Then we extract four extreme and interesting cases of the mass patterns. We connect these mass patterns with the Weinberg-Salam model, grand unification models such as SU(5), SO(10), and ${\mathrm{E}}_{6}$, and some constituent models. At the end of this paper we deduce from one of the interesting neutrino-mass patterns that one more neutral intermediate boson with mass at the same order as the mass of the $W$ boson may exist.