Quest for double beta decay of 160Gd and Ce isotopes Original Research Article

The 2β decay study of 160Gd has been performed in the Solotvina Underground Laboratory with the help of Gd2SiO5:Ce crystal scintillator (volume 95 cm3). The background of the detector in the vicinity of the Qββ energy of 160Gd was reduced to 1.0 cpd/(keV kg). The new improved half-life limits have been established for 0ν2β decay of 160Gd to the ground (0+) and first excited (2+) levels of 160Dy: T1/20ν⩾2.3(1.3)×1021 yr at 68%(90%) C.L. The T1/2 bounds have been also set for 2ν, 0νχ and 0νχχ modes of 160Gd decay, as well as for different 2β decay processes in 136Ce, 138Ce and 142Ce.