On the observability of Majoron emitting double beta decays

Because of the fine-tuning problem in classical Majoron models in recent years several new models were invented. It is pointed out that double beta decays with new Majoron emission depend on new matrix elements, which have not been considered in the literature. A calculation of these matrix elements and phase space integrals is presented. We find that for new Majoron models extremely small decay rates are expected.