Azzolini O, Beeman J W, Bellini F, Beretta M, Biassoni M, Brofferio C, Bucci C, Capelli S, Caracciolo V, Cardani L, Carniti P, Casali N, Chiesa D, Clemenza M, Colantoni I, Cremonesi O, Cruciani A, D'Addabbo A, Dafinei I, De Dominicis F, 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
INFN Laboratori Nazionali di Legnaro, I-35020 Legnaro (Pd), Italy.
Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
Phys Rev Lett. 2022 Sep 9;129(11):111801. doi: 10.1103/PhysRevLett.129.111801.
CUPID-0, an array of Zn^{82}Se cryogenic calorimeters, was the first medium-scale demonstrator of the scintillating bolometers' technology. The first project phase (March 2017-December 2018) allowed the most stringent limit on the neutrinoless double beta decay half-life of the isotope of interest, ^{82}Se, to be set. After a six month long detector upgrade, CUPID-0 began its second and last phase (June 2019-February 2020). In this Letter, we describe the search for neutrinoless double beta decay of ^{82}Se with a total exposure (phase I+II) of 8.82 kg yr^{-1} of isotope. We set a limit on the half-life of ^{82}Se to the ground state of ^{82}Kr of T_{1/2}^{0ν}(^{82}Se)>4.6×10^{24} yr (90% credible interval), corresponding to an effective Majorana neutrino mass m_{ββ}<(263-545) meV. We also set the most stringent lower limits on the neutrinoless decays of ^{82}Se to the 0_{1}^{+}, 2_{1}^{+}, and 2_{2}^{+} excited states of ^{82}Kr, finding 1.8×10^{23} yr, 3.0×10^{23} yr, and 3.2×10^{23} yr (90% credible interval) respectively.
CUPID - 0是一组Zn^{82}Se低温量热计，是闪烁热量计技术的首个中型示范装置。项目的第一阶段（2017年3月 - 2018年12月）确定了对感兴趣的同位素^{82}Se无中微子双β衰变半衰期的最严格限制。经过为期六个月的探测器升级后，CUPID - 0开始了其第二阶段也是最后阶段（2019年6月 - 2020年2月）。在本信函中，我们描述了对^{82}Se无中微子双β衰变的搜索，其总曝光量（第一阶段 + 第二阶段）为8.82 kg yr^{-1}的该同位素。我们设定了^{82}Se到^{82}Kr基态的半衰期限制为T_{1/2}^{0ν}(^{82}Se)>4.6×10^{24} yr（90%可信区间），对应有效马约拉纳中微子质量m_{ββ}<(263 - 545) meV。我们还对^{82}Se到^{82}Kr的0_{1}^{+}、2_{1}^{+}和2_{2}^{+}激发态的无中微子衰变设定了最严格的下限，分别为1.8×10^{23} yr、3.0×10^{23} yr和3.2×10^{23} yr（90%可信区间）。
