Final Result of CUPID-0 Phase-I in the Search for the Se 82 Neutrinoless Double- ? Decay

2019

PHYSICAL REVIEW LETTERS

Final Result of CUPID-0 Phase-I in the Search for the Se 82 Neutrinoless Double- ? Decay

01 Pubblicazione su rivista

Azzolini O., Beeman J. W., Bellini F., Beretta M., Biassoni M., Brofferio C., Bucci C., Capelli S., Cardani L., Carniti P., Casali N., Chiesa D., Clemenza M., Cremonesi O., Cruciani A., Dafinei I., Di Domizio S., Ferroni F., Gironi L., Giuliani A., Gorla P., Gotti C., Keppel G., Martinez M., Nagorny S., Nastasi M., Nisi S., Nones C., Orlandi D., Pagnanini L., Pallavicini M., Pattavina L., Pavan M., Pessina G., Pettinacci V., Pirro S., Pozzi S., Previtali E., Puiu A., Rusconi C., Schaffner K., Tomei C., Vignati M., Zolotarova A. S.

DOI: 10.1103/PhysRevLett.123.032501

ISSN: 1079-7114

CUPID-0 is the first pilot experiment of CUPID, a next-generation project for the measurement of neutrinoless double beta decay (0 nu DBD) with scintillating bolometers. The detector, consisting of 24 enriched and 2 natural ZnSe crystals, has been taking data at Laboratori Nazionali del Gran Sasso from June 2017 to December 2018, collecting a Se-82 exposure of 5.29 kg x yr. In this Letter we present the phase-I results in the search for O nu DBD. We demonstrate that the technology implemented by CUPID-0 allows us to reach the lowest background for calorimetric experiments: (3.5(-0.9)(+1.0)) x 10(-3) counts/ (keV kg yr). Monitoring 3.88 x 10(25) Se-82 nuclei x yr we reach a 90% credible interval median sensitivity of T-1/2(0 nu) > 5.0 x 10(24) yr and set the most stringent limit on the half-life of Se-82 O nu DBD: T-1/2(0 nu) > 3.5 x 10(24) yr (90% credible interval), corresponding to m(beta beta) < (311-638) meV depending on the nuclear matrix element calculations.

Majorana neutrinos neutrinless double beta decay