The neutrino as the supersymmetric partner of the majoron

Abstract We show that a supersymmetric extension of the standard SU (2) L ×U(1) model provides a natural framework for spontaneous breakdown of global lepton number symmetry leading to a “doublet” majoron with neutrino as its supersymmetric partner. A characteristic of this model is the appearance of a new contribution to neutrinoless double beta-decay (ββ)0ν mediated by the photino λγ which, however, is negligible for reasonable photino masses. We also predict the existence of a light mass (∼100 keV) scalar boson very weakly coupled to matter.