Properties of neutrinos in a class of gauge theories

We discuss the properties of neutrinos in a class of gauge theories characterized by manifest left-right symmetry and spontaneous genesis of parity nonconservation. Topics discussed in detail include: currents with anomalous Lorentz structure (herein called class III currents), electromagnetic properties of neutrinos, and rare processes involving neutrinos which are forbidden in the two-component theory. Calculations of the relevant coupling parameters and reaction rates are presented and compared to the best limits available from terrestrial experiments and astrophysical considerations. Some cosmological implications are also discussed, and it is suggested that all long-lived low-mass neutrinos have been discovered.