Quest for double beta decay of 160Gd and Ce isotopes

Abstract 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.