Search of the neutrino-less double beta decay of Se into the excited states of 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 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 Se into the 0 , 2 and 2 excited states of Kr with an exposure of 5.74 kg yr (2.24 10  emitters yr). We found no evidence of the decays and set the most stringent limits on the widths of these processes: ( Se Kr )8.55 10  yr , ( Se Kr )  yr , ( Se Kr )8.25 10  yr (90 credible interval).