Aurora experiment: Final results of studies of 116Cd 2β decay with enriched 116CdWO4 crystal scintillators

Abstract

Final results of studies of 116Cd 2β decay with CdWO4 crystal scintillators, enriched in 116Cd to 82%, are presented. After few years (2011 – 2017) of measurements with radiopure 116CdWO4 scintillators (mass of 1.162 kg) at the Gran Sasso underground laboratory (Italy), the half-life of 116Cd relatively to 2ν2β decay to the ground state of 116Sn was measured with the highest up-to-date accuracy as T1/2=(2.63−0.12+0.11)×1019 yr. A new limit on 0ν2β decay of 116Cd was set as T1/2≥2.2×1023 yr at 90% C.L., which is the most stringent to-date restriction for this isotope. Limits for 0ν2β decay with majoron(s) emission, Lorentz-violating 2ν2β decay and 2β transitions to excited states of 116Sn were set at the level of T1/2≥1020−1022 yr.Final results of studies of 116Cd 2β decay with CdWO4 crystal scintillators, enriched in 116Cd to 82%, are presented. After few years (2011 – 2017) of measurements with radiopure 116CdWO4 scintillators (mass of 1.162 kg) at the Gran Sasso underground laboratory (Italy), the half-life of 116Cd relatively to 2ν2β decay to the ground state of 116Sn was measured with the highest up-to-date accuracy as T1/2=(2.63−0.12+0.11)×1019 yr. A new limit on 0ν2β decay of 116Cd was set as T1/2≥2.2×1023 yr at 90% C.L., which is the most stringent to-date restriction for this isotope. Limits for 0ν2β decay with majoron(s) emission, Lorentz-violating 2ν2β decay and 2β transitions to excited states of 116Sn were set at the level of T1/2≥1020−1022 yr.