Systematic analysis of double-beta decay half lives

Evaluated 2β^- (2 ν) half-lives and their systematics were reexamined in the framework of a phenomenological approach. Decay rate dependence on nuclear deformation, decay energy, shape coexistence, and forbidden transitions was observed. The following analysis showed distinct impacts of decay energy on half lives, and deformation parameters on effective nuclear matrix elements. These findings were used to predict T_1/2 for 36 isotopes of interest. Present work results were compared with published data.