First Results of the Experiment to Search for 2β Decay of 106Cd with the Help of 106CdWO4 Crystal Scintillators.

An experiment to search for 2b processes in ¹⁰⁶Cd with the help of ¹⁰⁶CdWO₄ crystal scintillator (mass of 215 g), enriched in ¹⁰⁶Cd up to 66%, is in progress at the Gran Sasso National Laboratories of the INFN (Italy). After 1320 h of data taking, limits on double beta processes in ¹⁰⁶Cd have been established on the level of 10¹⁹-10²⁰ yr, in particular (all the results at 90% C.L.): T_1/2(0ν2[variant_greek_epsilon])>3.6×10²⁰ yr, T_1/2(2ν[variant_greek_epsilon]β⁺)>7.2×10¹⁹ yr, and T_1/2(2ν2β⁺)>2.5×10²⁰ yr. Resonant 0ν2[variant_greek_epsilon] processes have been restricted as T_1/2(0ν2K)>1.4×10²⁰ yr and T_1/2(0νLK)>3.2×10²⁰ yr. A possible resonant enhancement of the 0ν2[variant_greek_epsilon] processes is estimated in the framework of the QRPA approach. [ABSTRACT FROM AUTHOR]