First Result on the Neutrinoless Double-beta Decay of Se-82 with CUPID-0

We report the result of the search for neutrinoless double beta decay of Se-82 obtained with CUPID-0, the first large array of scintillating (ZnSe)-Se-82 cryogenic calorimeters implementing particle identification. We observe no signal in a 1.83 kg yr 82Se exposure, and we set the most stringent lower limit on the 0 nu beta beta 82Se half-life T-1/2(0 nu) > 2.4 x 10(24) yr (90% credible interval), which corresponds to an effective Majorana neutrino mass m beta beta < (376-770) meV depending on the nuclear matrix element calculations. The heat-light readout provides a powerful tool for the rejection of a particles and allows us to suppress the background in the region of interest down to (3.6(-1.4)(+1.9)) x 10(-3) counts / (keV kg yr), an unprecedented level for this technique.