First Results from CUORE: A Search for Lepton Number Violation via 0νββ Decay of Te130

Author(s): Alduino, C; Alessandria, F; Alfonso, K; Andreotti, E; Arnaboldi, C; Avignone, FT; Azzolini, O; Balata, M; Bandac, I; Banks, TI; Bari, G; Barucci, M; Beeman, JW; Bellini, F; Benato, G; Bersani, A; Biare, D; Biassoni, M; Bragazzi, F; Branca, A; Brofferio, C; Bryant, A; Buccheri, A; Bucci, C; Bulfon, C; Camacho, A; Caminata, A; Canonica, L; Cao, XG; Capelli, S; Capodiferro, M; Cappelli, L; Cardani, L; Cariello, M; Carniti, P; Carrettoni, M; Casali, N; Cassina, L; Cereseto, R; Ceruti, G; Chiarini, A; Chiesa, D; Chott, N; Clemenza, M; Conventi, D; Copello, S; Cosmelli, C; Cremonesi, O; Crescentini, C; Creswick, RJ; Cushman, JS; D'Addabbo, A; D'Aguanno, D; Dafinei, I; Datskov, V; Davis, CJ; Del Corso, F; Dell'Oro, S; Deninno, MM; Di Domizio, S; Di Vacri, ML; Di Paolo, L; Drobizhev, A; Ejzak, L; Faccini, R; Fang, DQ; Faverzani, M; Ferri, E; Ferroni, F | Abstract: © 2018 American Physical Society. The CUORE experiment, a ton-scale cryogenic bolometer array, recently began operation at the Laboratori Nazionali del Gran Sasso in Italy. The array represents a significant advancement in this technology, and in this work we apply it for the first time to a high-sensitivity search for a lepton-numberviolating process:130Te neutrinoless double-beta decay. Examining a total TeO2 exposure of 86.3 kg yr, characterized by an effective energy resolution of d7.7 ± 0.5T keV FWHM and a background in the region of interest of d0.014 ± 0.002T counts=dkeV kg yrT, we find no evidence for neutrinoless double-beta decay. Including systematic uncertainties, we place a lower limit on the decay half-life of T0ν1/2(130Te) g 1.3 × 1025yr (90% C.L.); the median statistical sensitivity of this search is 7.0 × 1024yr. Combining this result with those of two earlier experiments, Cuoricino and CUORE-0, we find T0ν1/2(130Te) g 1.5 × 1025yr (90% C.L.), which is the most stringent limit to date on this decay. Interpreting this result as a limit on the effective Majorana neutrino mass, we find mββl (110 - 520) meV, where the range reflects the nuclear matrix element estimates employed.