Investigation of ββ decay in 150Nd and 148Nd to the excited states of 150Sm and 148Sm

Abstract

Double beta decay of 150Nd and 148Nd to the excited states of daughter nuclei have been studied using a 400 cm3 low-background HPGe detector and an external source consisting of 3046 g of natural Nd2O3 powder. The half-life for the two-neutrino double beta decay of 150Nd to the excited 0+1 state in 150Sm is measured to be T1/2 = [1.33+0.36−0.23(stat)+0.27−0.13(syst)] · 1020 y. For other (0ν + 2ν) transitions to the 2+1, 2+2, 2+3, and 0+2 levels in 150Sm, limits are obtained at the level of ~ (2 − 8) · 1020 y. In the case of 148Nd only limits for the (0ν + 2ν) transitions to the 2+1, 0+1, and 2+2 excited states in 148Sm were obtained and are at the level of ~ (4 − 8) · 1020 y.