ABSTRACT
As pointed out in Section 16.5, clear-cut evidence of massive Majorana neutrinos can only be obtained from the observation of neutrinoless double beta decay, wherein a parent nucleus emits a pair of virtual W bosons which exchange a Majorana neutrino and produce the two emitted electrons. This chapter provides an outline of the derivation of the double beta decay rate, as well as a summary of the status of the experiments aimed at establishing the existence of the Majorana neutrino and determining its mass.
