Evidence of Single State Dominance in the Two-Neutrino Double-ß Decay of 82Se with CUPID-0

Azzolini, O. ; Beeman, J.\u2009W. ; Bellini, F. ; Beretta, M. ; Biassoni, M. ; Brofferio, C. ; Bucci, C. ; Capelli, S. ; Cardani, L. ; Carniti, P. ; Casali, N. ; Chiesa, D. ; Clemenza, M. ; Cremonesi, O. ; Cruciani, A. ; Dafinei, I. ; Di Domizio, S. ; Ferroni, F. ; Gironi, L. ; Giuliani, A. ; Gorla, P. ; Gotti, C. ; Keppel, G. ; Kotila, J. ; Martinez, M. (Universidad de Zaragoza) ; Nagorny, S. ; Nastasi, M. ; Nisi, S. ; Nones, C. ; Orlandi, D. ; Pagnanini, L. ; Pallavicini, M. ; Pattavina, L. ; Pavan, M. ; Pessina, G. ; Pettinacci, V. ; Pirro, S. ; Pozzi, S. ; Previtali, E. ; Puiu, A. ; Rusconi, C. ; Sch\u00e4ffner, K. ; Tomei, C. ; Vignati, M. ; Zolotarova, A.

Resumen: We report on the measurement of the two-neutrino double-β decay of Se82 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 ZnSe82, we determine the two-neutrino double-β decay half-life of Se82 with an unprecedented precision level, T1/22ν=[8.60±0.03(stat) -0.13+0.19(syst)]×1019 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.

Idioma: Inglés

DOI: 10.1103/physrevlett.123.262501

Año: 2019

Publicado en: Physical Review Letters 123, 26 (2019)
ISSN: 0031-9007

Factor impacto JCR: 8.385 (2019)

Categ. JCR: PHYSICS, MULTIDISCIPLINARY rank: 6 / 85 = 0.071 (2019) - Q1 - T1

Factor impacto SCIMAGO: 3.588 - Physics and Astronomy (miscellaneous) (Q1)

Financiación: info:eu-repo/grantAgreement/EC/FP7/247115/EU/Low-background Underground Cryogenic Installation For Elusive Rates/LUCIFER

Tipo y forma: Artículo (Versión definitiva)

Área (Departamento): Área Física Atóm.Molec.y Nucl. (Dpto. Física Teórica)