Complete event-by-event $\alpha/\gamma(\beta)$ separation in a full-size ${\mathrm{TeO}}_{2}$ CUORE bolometer by Neganov-Luke-magnified light detection - Archive ouverte HAL
Article Dans Une Revue Physical Review C Année : 2018

Complete event-by-event $\alpha/\gamma(\beta)$ separation in a full-size ${\mathrm{TeO}}_{2}$ CUORE bolometer by Neganov-Luke-magnified light detection

P. Camus
  • Fonction : Auteur

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.

Dates et versions

hal-01737889 , version 1 (20-03-2018)

Identifiants

Citer

L. Bergé, M. Chapellier, M. de Combarieu, L. Dumoulin, A. Giuliani, et al.. Complete event-by-event $\alpha/\gamma(\beta)$ separation in a full-size ${\mathrm{TeO}}_{2}$ CUORE bolometer by Neganov-Luke-magnified light detection. Physical Review C, 2018, 97 (3), pp.032501. ⟨10.1103/PhysRevC.97.032501⟩. ⟨hal-01737889⟩
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