寻找82硒无中微子双β衰变的CUPID-0一期实验最终结果。

Final Result of CUPID-0 Phase-I in the Search for the ^{82}Se Neutrinoless Double-β Decay.

作者信息

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, Schäffner K, Tomei C, Vignati M, Zolotarova A S

机构信息

INFN Laboratori Nazionali di Legnaro, I-35020 Legnaro (Pd), Italy.

Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.

出版信息

Phys Rev Lett. 2019 Jul 19;123(3):032501. doi: 10.1103/PhysRevLett.123.032501.

DOI:10.1103/PhysRevLett.123.032501

PMID:31386478

Abstract

CUPID-0 is the first pilot experiment of CUPID, a next-generation project for the measurement of neutrinoless double beta decay (0νDBD) 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 ^{82}Se exposure of 5.29 kg×yr. In this Letter we present the phase-I results in the search for 0νDBD. 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})×10^{-3} counts/(keV kg yr). Monitoring 3.88×10^{25} ^{82}Se nuclei×yr we reach a 90% credible interval median sensitivity of T_{1/2}^{0ν}>5.0×10^{24} yr and set the most stringent limit on the half-life of ^{82}Se 0νDBD: T_{1/2}^{0ν}>3.5×10^{24} yr (90% credible interval), corresponding to m_{ββ}<(311-638) meV depending on the nuclear matrix element calculations.

摘要

CUPID-0是CUPID的首个试点实验，CUPID是一个利用闪烁热量计测量无中微子双β衰变（0νDBD）的下一代项目。该探测器由24个富集的和2个天然的ZnSe晶体组成，于2017年6月至2018年12月在大萨索国家实验室采集数据，收集到的(^{82}Se)曝光量为5.29 kg×年。在本信函中，我们展示了寻找0νDBD的第一阶段结果。我们证明，CUPID-0所采用的技术使我们能够达到量热实验的最低本底：((3.5_{-0.9}^{+1.0})×10^{-3})计数/（keV·kg·年）。通过监测(3.88×10^{25})(^{82}Se)原子核×年，我们达到了(T_{1/2}^{0ν}>5.0×10^{24})年的90%可信区间中位数灵敏度，并对(^{82}Se) 0νDBD的半衰期设定了最严格的限制：(T_{1/2}^{0ν}>3.5×10^{24})年（90%可信区间），根据核矩阵元计算，这对应于(m_{ββ}<(311 - 638)) meV。