Complete event-by-event $\alpha/\gamma(\beta)$ separation in a full-size ${\mathrm{TeO}}_{2}$ CUORE bolometer by Neganov-Luke-magnified light detection
2 SPEC - UMR3680 - Service de physique de l'état condensé
3 LC - Laboratoire de Cryogénie
4 IRFU - Institut de Recherches sur les lois Fondamentales de l'Univers
5 EKP - Institut für Experimentelle Kernphysik [Karlsruhe]
6 DPhP - Département de Physique des Particules (ex SPP)
7 IPNL - Institut de Physique Nucléaire de Lyon
8 NEEL - HELFA - Hélium : du fondamental aux applications
9 NEEL - Cryo - Cryogénie
10 KIT - Karlsruhe Institute of Technology = Karlsruher Institut für Technologie
11 C2N - Centre de Nanosciences et de Nanotechnologies [Orsay]
12 IPE - Institut für Prozessdatenverarbeitung und Elektronik
13 Department of Physics [Oxford]
14 Department of Physics and Astronomy [Sheffield]
15 QUANTRONICS - Quantronics Group
16 DEDIP - Département d'Electronique, des Détecteurs et d'Informatique pour la Physique (ex SEDI)
17 DLNP - Dzhelepov Laboratory of Nuclear Problems [Dubna]
- Fonction : Auteur
- PersonId : 1605654
- IdHAL : valentina-novati
- ORCID : 0000-0003-0922-0475
- Fonction : Auteur
- PersonId : 980046
- IdRef : 117614165
- Fonction : Auteur
- PersonId : 180518
- IdHAL : helene-le-sueur
Résumé
In the present work, we describe the results obtained with a large (≈133cm3) TeO2 bolometer, with a view to a search for neutrinoless double-β decay (0νββ) of Te130. We demonstrate an efficient α-particle discrimination (99.9%) with a high acceptance of the 0νββ signal (about 96%), expected at ≈2.5 MeV. This unprecedented result was possible thanks to the superior performance (10-eV rms baseline noise) of a Neganov-Luke-assisted germanium bolometer used to detect a tiny (70-eV) light signal from the TeO2 detector, dominated by γ(β)-induced Cherenkov radiation but exhibiting also a clear scintillation component. The obtained results represent a major breakthrough toward the TeO2-based version of the CUORE Upgrade with Particle IDentification (CUPID), a ton-scale cryogenic 0νββ experiment proposed as a followup to the Cryogenic Underground Observatory for Rare Events (CUORE) project with particle identification. The CUORE experiment recently began a search for neutrinoless double-β decay of Te130 with an array of 988 125-cm3TeO2 bolometers. The lack of α discrimination in CUORE makes α decays at the detector surface the dominant background component, at the level of ≈0.01 counts/(keV kg y) in the region of interest. We show here, for the first time with a CUORE-size bolometer and using the same technology as CUORE for the readout of both heat and light signals, that surface α background can be fully rejected.