Double beta decay results from the CUPID-0 experiment

TL;DR

The CUPID-0 experiment demonstrated advanced scintillating cryogenic calorimeters capable of background rejection and set new limits on neutrinoless double beta decay of $^{82}$Se, advancing the search for neutrino properties.

Contribution

This paper presents the final results of CUPID-0 Phase I, including background modeling, measurement of $^{82}$Se 2$ u$DBD half-life, and evidence of single state dominance in the nuclear transition.

Findings

Complete rejection of alpha background achieved.

Set the most stringent limit on $^{82}$Se 0$ u$DBD.

Measured $^{82}$Se 2$ u$DBD half-life.

Abstract

A convincing observation of neutrino-less double beta decay (0$\nu$DBD) relies on the possibility of operating high energy-resolution detectors in background-free conditions. Scintillating cryogenic calorimeters are one of the most promising tools to fulfill the requirements for a next-generation experiment. Several steps have been taken to demonstrate the maturity of this technique, starting from the successful experience of CUPID-0. The CUPID-0 experiment demonstrated the complete rejection of the dominant alpha background measuring the lowest counting rate in the region of interest for this technique. Furthermore, the most stringent limit on the $^{82}$Se 0$\nu$DBD was established running 26 ZnSe crystals during two years of continuous detector operation. In this contribution we present the final results of CUPID-0 Phase I including a detailed model of the background, the measurement of the $^{82}$Se 2$\nu$DBD half-life and the evidence that this nuclear transition is single state dominated.