New Limit for Neutrinoless Double-Beta Decay of ¹⁰⁰Mo from the CUPID-Mo Experiment

The CUPID-Mo experiment at the Laboratoire Souterrain de Modane (France) is a demonstrator for CUPID, the next-generation ton-scale bolometric 0νββ experiment. It consists of a 4.2 kg array of 20 enriched Li${}_2^{100}$MoO${}_4$ scintillating bolometers to search for the lepton-number-violating process of 0νββ decay in ${}^{100}$Mo. With more than one year of operation (${}^{100}$Mo exposure of 1.17  kg×yr for physics data), no event in the region of interest and, hence, no evidence for 0νββ is observed. We report a new limit on the half-life of 0νββ decay in ${}^{100}$Mo of T${}_{1/2}$>1.5×10${}^{24}$  yr at 90% C.I. The limit corresponds to an effective Majorana neutrino mass ⟨m${}_{\beta \beta }$⟩<(0.31–0.54)  eV, dependent on the nuclear matrix element in the light Majorana neutrino exchange interpretation.