Deformed shell model results for two-neutrino positron double beta decay of 84Sr

Half-lives T1/22ν for two-neutrino positron double beta decay modes β+EC/ECEC are calculated for 84Sr, a nucleus of current experimental interest, within the framework of the deformed shell model based on Hartree–Fock states employing a modified Kuo interaction in (2p3/2, 1f5/2, 2p1/2, 1g9/2) space. For a reasonable description of the spectra of 84Sr and 84Kr and to generate allowed GT strengths, the single particle energies of the proton and neutron 1g9/2 orbitals, relative to the 2p3/2 orbital energy, are chosen to be 3.5 MeV and 1.5 MeV for both 84Sr and 84Rb and 1.5 MeV and 1.5 MeV for 84Kr. With this, the calculated half-lives for the β+EC and ECEC modes are ~1026yr and ~4×1024yr respectively. (author)