Result on the Neutrinoless Double Beta Decay Search of 82Se with the CUPID-0 Experiment

CUPID-0 is the first large array of scintillating Zn82Se cryogenic calorimeters (bolometers) implementing particle identification for the search of the neutrinoless double beta decay (0nbb). The detector consists of 24 enriched Zn82Se bolometers for a total 82Se mass of 5.28 kg and it has been taking data in the underground LNGS (Italy) since March 2017. In this article we show how the dual read-out provides a powerful tool for the a particles rejection. The simultaneous use of the heat and light information allows us to reduce the background down to (3.2+1.3 1.1)103counts/(keV kg year), an unprecedented level for cryogenic calorimeters. In a total exposure of 5.46 kg year Zn82Se we set the most stringent limit on the 0nbb decay 82Se half-life T0n 1/2 > 4.0 1024 year at 90% C.I.