Search for Neutrinoless Double-β Decay with the Complete EXO-200 Dataset

G Anton; I Badhrees; P S Barbeau; D Beck; V Belov; T Bhatta; M Breidenbach; T Brunner; G F Cao; W R Cen; C Chambers; B Cleveland; M Coon; A Craycraft; T Daniels; M Danilov; L Darroch; S J Daugherty; J Davis; S Delaquis; A Der Mesrobian-Kabakian; R DeVoe; J Dilling; A Dolgolenko; M J Dolinski; J Echevers; W Fairbank; D Fairbank; J Farine; S Feyzbakhsh; P Fierlinger; D Fudenberg; P Gautam; R Gornea; G Gratta; C Hall; E V Hansen; J Hoessl; P Hufschmidt; M Hughes; A Iverson; A Jamil; C Jessiman; M J Jewell; A Johnson; A Karelin; L J Kaufman; T Koffas; R Krücken; A Kuchenkov; K S Kumar; Y Lan; A Larson; B G Lenardo; D S Leonard; G S Li; S Li; Z Li; C Licciardi; Y H Lin; R MacLellan; T McElroy; T Michel; B Mong; D C Moore; K Murray; O Njoya; O Nusair; A Odian; I Ostrovskiy; A Piepke; A Pocar; F Retière; A L Robinson; P C Rowson; D Ruddell; J Runge; S Schmidt; D Sinclair; A K Soma; V Stekhanov; M Tarka; J Todd; T Tolba; T I Totev; B Veenstra; V Veeraraghavan; P Vogel; J-L Vuilleumier; M Wagenpfeil; J Watkins; M Weber; L J Wen; U Wichoski; G Wrede; S X Wu; Q Xia; D R Yahne; L Yang; Y-R Yen; O Ya Zeldovich; T Ziegler; EXO-200 Collaboration

doi:10.1103/PhysRevLett.123.161802

Search for Neutrinoless Double-β Decay with the Complete EXO-200 Dataset

Phys Rev Lett. 2019 Oct 18;123(16):161802. doi: 10.1103/PhysRevLett.123.161802.

Authors

G Anton¹, I Badhrees², P S Barbeau³, D Beck⁴, V Belov⁵, T Bhatta⁶, M Breidenbach⁷, T Brunner^{8

9}, G F Cao¹⁰, W R Cen¹⁰, C Chambers¹¹, B Cleveland¹², M Coon⁴, A Craycraft¹¹, T Daniels¹³, M Danilov⁵, L Darroch⁸, S J Daugherty¹⁴, J Davis⁷, S Delaquis⁷, A Der Mesrobian-Kabakian¹², R DeVoe¹⁵, J Dilling⁹, A Dolgolenko⁵, M J Dolinski¹⁶, J Echevers⁴, W Fairbank¹¹, D Fairbank¹¹, J Farine¹², S Feyzbakhsh¹⁷, P Fierlinger¹⁸, D Fudenberg¹⁵, P Gautam¹⁶, R Gornea^{2

9}, G Gratta¹⁵, C Hall¹⁹, E V Hansen¹⁶, J Hoessl¹, P Hufschmidt¹, M Hughes²⁰, A Iverson¹¹, A Jamil²¹, C Jessiman², M J Jewell¹⁵, A Johnson⁷, A Karelin⁵, L J Kaufman⁷, T Koffas², R Krücken⁹, A Kuchenkov⁵, K S Kumar²², Y Lan⁹, A Larson⁶, B G Lenardo¹⁵, D S Leonard²³, G S Li¹⁵, S Li⁴, Z Li²¹, C Licciardi¹², Y H Lin¹⁶, R MacLellan⁶, T McElroy⁸, T Michel¹, B Mong⁷, D C Moore²¹, K Murray⁸, O Njoya²², O Nusair²⁰, A Odian⁷, I Ostrovskiy²⁰, A Piepke²⁰, A Pocar¹⁷, F Retière⁹, A L Robinson¹², P C Rowson⁷, D Ruddell¹³, J Runge³, S Schmidt¹, D Sinclair^{2

9}, A K Soma²⁰, V Stekhanov⁵, M Tarka¹⁷, J Todd¹¹, T Tolba¹⁰, T I Totev⁸, B Veenstra², V Veeraraghavan²⁰, P Vogel²⁴, J-L Vuilleumier²⁵, M Wagenpfeil¹, J Watkins², M Weber¹⁵, L J Wen¹⁰, U Wichoski¹², G Wrede¹, S X Wu¹⁵, Q Xia²¹, D R Yahne¹¹, L Yang⁴, Y-R Yen¹⁶, O Ya Zeldovich⁵, T Ziegler¹; EXO-200 Collaboration

Affiliations

¹ Erlangen Centre for Astroparticle Physics, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen 91058, Germany.
² Physics Department, Carleton University, Ottawa, Ontario K1S 5B6, Canada.
³ Department of Physics, Duke University, and Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708, USA.
⁴ Physics Department, University of Illinois, Urbana-Champaign, Illinois 61801, USA.
⁵ Institute for Theoretical and Experimental Physics named by A.I. Alikhanov of National Research Center "Kurchatov Institute," 117218 Moscow, Russia.
⁶ Department of Physics, University of South Dakota, Vermillion, South Dakota 57069, USA.
⁷ SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA.
⁸ Physics Department, McGill University, Montreal H3A 2T8, Quebec, Canada.
⁹ TRIUMF, Vancouver, British Columbia V6T 2A3, Canada.
¹⁰ Institute of High Energy Physics, Beijing 100049, China.
¹¹ Physics Department, Colorado State University, Fort Collins, Colorado 80523, USA.
¹² Department of Physics, Laurentian University, Sudbury, Ontario P3E 2C6, Canada.
¹³ Department of Physics and Physical Oceanography, University of North Carolina at Wilmington, Wilmington, North Carolina 28403, USA.
¹⁴ Physics Department and CEEM, Indiana University, Bloomington, Indiana 47405, USA.
¹⁵ Physics Department, Stanford University, Stanford, California 94305, USA.
¹⁶ Department of Physics, Drexel University, Philadelphia, Pennsylvania 19104, USA.
¹⁷ Amherst Center for Fundamental Interactions and Physics Department, University of Massachusetts, Amherst, Massachusetts 01003, USA.
¹⁸ Physik Department and Excellence Cluster Universe, Technische Universität München, Garching 80805, Germany.
¹⁹ Physics Department, University of Maryland, College Park, Maryland 20742, USA.
²⁰ Department of Physics and Astronomy, University of Alabama, Tuscaloosa, Alabama 35487, USA.
²¹ Wright Laboratory, Department of Physics, Yale University, New Haven, Connecticut 06511, USA.
²² Department of Physics and Astronomy, Stony Brook University, SUNY, Stony Brook, New York 11794, USA.
²³ IBS Center for Underground Physics, Daejeon 34126, Korea.
²⁴ Kellogg Lab, Caltech, Pasadena, California 91125, USA.
²⁵ LHEP, Albert Einstein Center, University of Bern, Bern CH-3012, Switzerland.

PMID: 31702371
DOI: 10.1103/PhysRevLett.123.161802

Abstract

A search for neutrinoless double-β decay (0νββ) in ^{136}Xe is performed with the full EXO-200 dataset using a deep neural network to discriminate between 0νββ and background events. Relative to previous analyses, the signal detection efficiency has been raised from 80.8% to 96.4±3.0%, and the energy resolution of the detector at the Q value of ^{136}Xe 0νββ has been improved from σ/E=1.23% to 1.15±0.02% with the upgraded detector. Accounting for the new data, the median 90% confidence level 0νββ half-life sensitivity for this analysis is 5.0×10^{25} yr with a total ^{136}Xe exposure of 234.1 kg yr. No statistically significant evidence for 0νββ is observed, leading to a lower limit on the 0νββ half-life of 3.5×10^{25} yr at the 90% confidence level.