Search of the neutrino-less double beta decay of 82 Se into the excited states of 82 Kr with CUPID-0

Abstract

The CUPID-0 experiment searches for double beta decay using cryogenic calorimeters with double (heat and light) read-out. The detector, consisting of 24 ZnSe crystals 95% enriched in 82Se and two natural ZnSe crystals, started data-taking in 2017 at Laboratori Nazionali del Gran Sasso. We present the search for the neutrino-less double beta decay of 82Se into the 01+, 21+ and 22+ excited states of 82Kr with an exposure of 5.74 kg· yr (2.24× 1025 emitters· yr). We found no evidence of the decays and set the most stringent limits on the widths of these processes: Γ(82Se → 82Kr01+)8.55× 10- 24 yr- 1, Γ (82 Se → 82 Kr 21+)<6.25×10-24 yr- 1, Γ(82Se → 82Kr22+)8.25× 10- 24 yr- 1 (90% credible interval).