Common explanation for the atmospheric, solar-neutrino, and double-β decay anomalies

Acker and co-workers have recently proposed an economical solution to the solar and atmospheric neutrino deficits, in which both are explained by large-angle νe-νμ oscillations, supplemented by νe decays. We show how to embed their phenomenological model into an electroweak framework in which global electron and muon numbers, [U(1)e×U(1)μ], spontaneously break at a scale of 1 ke V. Despite such a low scale, our model is technically natural. The …