6533b824fe1ef96bd12810cb

RESEARCH PRODUCT

Evidence of Single State Dominance in the Two-Neutrino Double-β Decay of ^{82}Se with CUPID-0.

O. AzzoliniJ.  W. BeemanF. BelliniM. BerettaM. BiassoniC. BrofferioC. BucciS. CapelliL. CardaniP. CarnitiN. CasaliD. ChiesaM. ClemenzaO. CremonesiA. CrucianiI. DafineiS. Di DomizioF. FerroniL. GironiA. GiulianiP. GorlaC. GottiG. KeppelJ. KotilaM. MartinezS. NagornyM. NastasiS. NisiC. NonesD. OrlandiL. PagnaniniM. PallaviciniL. PattavinaM. PavanG. PessinaV. PettinacciS. PirroS. PozziE. PrevitaliA. PuiuC. RusconiK. SchäffnerC. TomeiM. VignatiA. Zolotarova

subject

two-neutrinos double-β decay; nuclear matrix elements; scintillating cryogenic calorimetersDouble beta decay exited states nuclear modelnuclear matrix elementshiukkasfysiikkaydinfysiikkatwo-neutrinos double-β decayscintillating cryogenic calorimeters

description

We report on the measurement of the two-neutrino double-β decay of ^{82}Se performed for the first time with cryogenic calorimeters, in the framework of the CUPID-0 experiment. With an exposure of 9.95 kg yr of Zn^{82}Se, we determine the two-neutrino double-β decay half-life of ^{82}Se with an unprecedented precision level, T_{1/2}^{2ν}=[8.60±0.03(stat) _{-0.13}^{+0.19}(syst)]×10^{19}  yr. The very high signal-to-background ratio, along with the detailed reconstruction of the background sources allowed us to identify the single state dominance as the underlying mechanism of such a process, demonstrating that the higher state dominance hypothesis is disfavored at the level of 5.5σ.

10.1103/physrevlett.123.262501https://pubmed.ncbi.nlm.nih.gov/31951429