Final results on the 0νββ decay half-life limit of 100Mo from the CUPID-Mo experiment

The CUPID-Mo experiment to search for 0 nu beta beta decay in Mo-100 has been recently completed after about 1.5 years of operation at Laboratoire Souterrain de Modane (France). It served as a demonstrator for CUPID, a next generation 0 nu beta beta decay experiment. CUPID-Mo was comprised of 20 enriched Li-2 (MoO4)-Mo-100 scintillating calorimeters, each with a mass of similar to 0.2 kg, operated at similar to 20 mK. We present here the final analysis with the full exposure of CUPID-Mo (Mo-100 exposure of 1.47 kg x year) used to search for lepton number violation via 0 nu beta beta decay. We report on various analysis improvements since the previous result on a subset of data, reprocessing all data with these new techniques. We observe zero events in the region of interest and set a new limit on the Mo-100 0 nu beta beta decay half-life of T-1/2(0 nu) > 1.8 x 10(24) year (stat. + syst.) at 90% CI. Under the light Majorana neutrino exchange mechanism this corresponds to an effective Majorana neutrino mass of < m(beta beta)> < (0.28-0.49) eV, dependent upon the nuclear matrix element utilized.

Automated summary

The CUPID-Mo experiment, a search for Mo-100 0νββ decay, has been completed in France after 1.5 years of operation. It served as a demonstration for the CUPID experiment and used 20 scintillating calorimeters with a mass of 0.2 kg each. The final analysis showed no events in the region of interest and set a new limit on the Mo-100 0νββ decay half-life.