Result on the neutrinoless double beta decay search of 82 Se with the CUPID-0 experiment

Abstract

CUPID-0 is the first large array of scintillating Zn 82 Se cryogenic calorimeters (bolometers) implementing particle identification for the search of the neutrinoless double beta decay (0vββ). The detector consists of 24 enriched Zn 82 Se bolometers for a total 82 Se 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 +1.31.1 x10 -3 counts/(keV kg year), an unprecedented level for cryogenic calorimeters. In a total exposure of 5.46 kg year Zn 82 Se we set the most stringent limit on the 0vββ decay 82 Se half-life T 0v1/2 ≤ 4.0 x 10 24 year at 90% C.I.