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

The CUPID-Mo experiment to search for 0νββ decay in $^{100}$Mo 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 0νββ decay experiment. CUPID-Mo was comprised of 20 enriched Li$_2^{100}$MoO$_4$ scintillating calorimeters, each with a mass of ∼0.2 kg, operated at ∼20 mK. We present here the final analysis with the full exposure of CUPID-Mo ($^{100}$Mo exposure of 1.47 kg×year) used to search for lepton number violation via 0νββ 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 $^{100}$Mo 0νββ decay half-life of T$^{0ν}_{1/2}$ >1.8×10$^{24}$ year (stat. + syst.) at 90% CI. Under the light Majorana neutrino exchange mechanism this corresponds to an effective Majorana neutrino mass of ⟨m$_{ββ}$⟩ < (0.28−0.49) eV, dependent upon the nuclear matrix element utilized.