Neutrino Mass, the Right-Handed Interaction and the Double Beta Decay. II: General Properties and Data Analysis

Based on the formulae for the double β decay obtained in the previous paper, the general properties of 0+ →J+ transitions are discussed and the analysis of the experimental data is presented. It is found that, for the two neutrino mode, the 0+ →0+ transition in the two nucleon (2n)-mechanism dominates over the 0+ →2+ transition as well as the contribution from the N*-mechanism. For the neutrinoless mode, only the 0+ →0+ transition in the 2n-mechanism is allowed if there is no right-handed interaction. When the right-handed interaction gives a sizable contribution, the role of the 0+ →2+ transition becomes as important as the 0+ →0+ transition in this mode. It is concluded that the experimental data on the ratio of the 128Te to 130Te half-lives by Hennecke et al. suggest that neutrinos are Majorana particles, if we take the Vergados estimation of the nuclear matrix elements. Moreover, we find that the weighted average of neutrino masses is around 34 eV if there is no right-handed interaction.