Observable majoron emission in neutrinoless double beta decay

Abstract

We consider a class of simplest majoron models where neutrino-majoron couplings can be in the range g∼ 10 −5−10 −3, leading to the observability of neutrinoless double beta decay with majoron emission. The majoron is a singlet (or mostly a singlet) of the electroweak SU(2)⊗U(1) gauge symmetry, thus avoiding conflict with the LEP data on Z-decay, which rules out the triplet and doublet majoron models. Some aspects of the phenomenology of such models are discussed.