Search for 2β decay of cerium isotopes with CeCl3 scintillator

Double beta processes in 136Ce, 138Ce and 142Ce have been searched for by exploiting the active source approach with the help of a 6.9 g CeCl3 crystal as a scintillator for the first time at the Gran Sasso National Laboratory (LNGS) of the INFN (Italy). The total measurement time is 1638 h; even such a small exposure has allowed the achievement of some improved half-life limits on 2β decay processes in these isotopes at the level of 1016-1018 yr. In particular (90% C.L.): T0νɛβ+1/2(136Ce) >= 8.8 × 1016 yr, T2νɛβ+1/2(136Ce) >=2.4 × 1016 yr, T2ν2K1/2(136Ce) >=3.2 × 1016 yr, T2ν2K1/2(138Ce) >=4.4 × 1016 yr, and T2ν2β-1/2(142Ce) >=1.4 × 1018 yr. Possible future perspectives are also briefly addresse