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

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 82 Se 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 82 Se into the 0 1+ , 2 1+ and 2 2+ excited states of 82 Kr with an exposure of 5.74 kg  ·  yr (2.24  ×  10 25  emitters  ·  yr). We found no evidence of the decays and set the most stringent limits on the widths of these processes: Γ ( 82 Se →82 Kr 01+ )8.55  ×  10 -24  yr -1 , Γ ( 82 Se →82 Kr 21+ )  <  6.25  ×  10-24  yr -1 , Γ ( 82 Se →82 Kr 22+ )8.25  ×  10 -24  yr -1 (90 % credible interval).