학술논문

Search for neutrinoless β+EC decay of Te120 with CUORE
Document Type
article
Source
Physical Review C. 105(6)
Subject
Nuclear and Plasma Physics
Particle and High Energy Physics
Synchrotrons and Accelerators
Physical Sciences
Nuclear and plasma physics
Language
Abstract
The Cryogenic Underground Observatory for Rare Events (CUORE) is a large-scale cryogenic experiment searching for neutrinoless double-beta decay (0νββ) in Te130. The CUORE detector is made of natural tellurium, providing the possibility of rare event searches on isotopes other than Te130. In this work we describe a search for neutrinoless positron-emitting electron capture (β+EC) decay in Te120 with a total TeO2 exposure of 355.7 kg yr, corresponding to 0.2405 kg yr of Te120. Albeit 0νββ with two final-state electrons represents the most promising channel, the emission of a positron and two 511-keV γ's make 0νβ+EC decay signature extremely clear. To fully exploit the potential offered by the detector modularity we include events with different topology and perform a simultaneous fit of five selected signal signatures. Using blinded data we extract a median exclusion sensitivity of 3.4×1022 yr at 90% credibility interval (C.I.). After unblinding we find no evidence of 0νβ+EC signal and set a 90% C.I. Bayesian lower limit of 2.9×1022 yr on Te120 half-life. This result improves by an order of magnitude the existing limit from the combined analysis of CUORE-0 and Cuoricino.