Nuclear Structure Calculations for Two-Neutrino Double-β Decay

Abstract EN

We study the two-neutrino double- β decay in 76Ge, 116Cd, 128Te, 130Te, and 150Nd, as well as the two Gamow-Teller branches that connect the double- β decay partners with the states in the intermediate nuclei.

We use a theoretical microscopic approach based on a deformed self-consistent mean field with Skyrme interactions including pairing and spin-isospin residual forces, which are treated in a proton-neutron quasiparticle random-phase approximation.

We compare our results for Gamow-Teller strength distributions with experimental information obtained from charge-exchange reactions.

We also compare our results for the two-neutrino double- β decay nuclear matrix elements with those extracted from the measured half-lives.

Both single-state and low-lying-state dominance hypotheses are analyzed theoretically and experimentally making use of recent data from charge-exchange reactions and β decay of the intermediate nuclei.