Neutrino Mass, the Right-Handed Interaction and the Double Beta Decay. I: Formalism

Abstract

In order to shed light on the important question whether neutrinos are Dirac or Majorana particles, the double fJ decay is investigated within a general form of weak interaction Hamil· tonian. . The systematic study is made on the 0+ ~ J+ nuclear transitions for the two-neutrino and neutrinoless modes both in the two-nucleon-and N*-mechanism. It is shown that for the neutrinoless mode, only the 0+ -0+ transition in the two-nucleon mechanism is allowed if there is no right-handed interaction. When the right-handed interaction gives a sizable contribution, the role of the 0+ ~ z+ transition becomes as important as the 0+ ~ 0+ transition. The com-parison of our results with the previous ones is also presented.