The half-life for two-neutrino double-beta decay has been calculated for 82Se, within the framework of the deformed shell model (DSM) based on Hartree–Fock states employing a modified Kuo interaction in 2p3/2, 1f5/2, 2p1/2, and 1g9/2 space with single particle energies (relative to a 56Ni core) for the four orbitals taken as 0.0, 0.78, 1.08, and 4.25 MeV, respectively. A reasonable description is obtained for the spectroscopic properties of yrast levels in 82Se, and similarly in the past 82Kr was studied successfully using DSM. The half-life calculated using DSM is ∼3.56 × 1020 a compared to the experimental value (0.92 ± 0.07) × 1020 a. We have also recalculated the half-life by including the 1f7/2 orbit in the preceding model space using the fpg interaction introduced by Sorlin et al. (Phys. Rev. Lett. 88, 092501 (2002)). The calculated half-life is 2.05 × 1019 a (0.58 × 1020 a if we include the quenching factor of 0.77).
Shell-Model Investigation of Electromagnetic Properties of 57Ni and 55Co