LocalB−LSymmetry of Electroweak Interactions, Majorana Neutrinos, and Neutron Oscillations

Abstract

Interpretation of the U(1) generator of the left-right-symmetric electroweak model in terms of $B\ensuremath{-}L$ enables us to study the spontaneous breaking of local $B\ensuremath{-}L$ symmetry. The same Higgs mechanism at the "partial unification" level of $\mathrm{SU}{(2)}_{L}\ensuremath{\bigotimes}\mathrm{SU}{(2)}_{R}\ensuremath{\bigotimes}\mathrm{SU}({4}^{\ensuremath{'}})$ that produces ${\ensuremath{\Delta}}_{L}=2$ processes (e.g., Majorana neutrinos) also yields $\ensuremath{\Delta}B=2$ processes (e.g., "neutron oscillations"). The observation of "neutrinoless" double $\ensuremath{\beta}$ decay and $\ensuremath{\Delta}B=2$ nucleon transitions without proton decay would favor this model and an intermediate mass scale.