Search for inclusive double beta decay of 150Nd to excited states of 150Sm at Laboratori Nazionali del Gran Sasso
Double beta decay to excited states of daughter nuclei is poorely studied (even if evidence for the decay has been recently reported). Measurements were performed at Laboratori Nazionali del Gran Sasso with a germanium detector, by searching for the de-excitation gamma rays of the daughter nuclides. New lower limits on the half-lives for double beta decay of 150Nd to excited states of 150Sm have been obtained. They range between 6×10 19 and 10×10 19 years (90% C.L.). A further measurement on 6 kg of natural Nd is in progress, preliminary results and a detailed study of intrinsic radioactivity of the sample are presented.