6533b83afe1ef96bd12a7795

RESEARCH PRODUCT

Systematic study of the single-state dominance in 2νββ decay transitions

subject

description

Abstract The single-state-dominance hypothesis (SSDH) states that the decay rates of the two-neutrino double-beta decay are governed by a virtual two-step transition connecting the initial and final ground states through the first 1 + state, 1 l + , of the intermediate odd-odd nucleus, for those odd-odd nuclei where the 1 l + state is the ground state. To investigate the validity of the SSDH we have performed a systematical theoretical analysis of all known double-beta-decay transitions where the SSDH conditions are fulfilled. the calculations are based on the quasiparticle random-phase approximation (QRPA) and the results have been obtained by using realistic single-particle bases and realistic interactions. We have studied the double β − decays of 100 Mo, 110 Pd, 114 Cd, 116 Cd and 128 Te and the double electron-capture transitions in 106 Cd and 136 Ce. The analysis shows that the SSDH is realized either through a true dominance of the first intermediate 1 + state or by cancellations among the contributions of higher lying 1 + states of the intermediate nucleus.