Large-scale shell-model study of two-neutrino double beta decay of 82Se, 94Zr, 108Cd, 124Sn, 128Te, 130Te, 136Xe, and 150Nd

Abstract

Large-scale shell-model calculations have been performed for the study of two-neutrino double-beta ($2\nu \beta \beta$) decay in ⁸²Se, ⁹⁴Zr, ¹⁰⁸Cd, ¹²⁴Sn, ¹²⁸Te, ¹³⁰Te, ¹³⁶Xe, and ¹⁵⁰Nd. We have employed JUN45 interaction to calculate the nuclear matrix element (NME) for $2\nu \beta \beta$ decay in ⁸²Se. In the case of ⁹⁴Zr, the glekpn effective interaction is used. For ¹⁰⁸Cd, we have used a realistic effective interaction derived through the G-matrix approach. In the case of ¹²⁴Sn, ^128,130Te and ¹³⁶Xe, the sn100pn effective interaction is employed. For ¹⁵⁰Nd, we have used KHHE effective interaction based on holes in a ²⁰⁸Pb core. We have extracted the half-lives of these nuclei for the $2\nu \beta \beta$ decay with the help of calculated NME. Our results are consistent with the available experimental half-lives. The variation of cumulative $2\nu \beta \beta$ NME with respect to the excitation energy of the intermediate $1^{+}$ states is also shown, and in all cases, it is ensured that their values are almost saturated. In the present work we have calculated more intermediate $1^{+}$ states as much as possible in comparison to results available in the literature.