Abstract
Results from a search for neutrinoless double-beta decay (0νββ) of Xe136 are presented using the first year of data taken with the upgraded EXO-200 detector. Relative to previous searches by EXO-200, the energy resolution of the detector has been improved to σ/E=1.23%, the electric field in the drift region has been raised by 50%, and a system to suppress radon in the volume between the cryostat and lead shielding has been implemented. In addition, analysis techniques that improve topological discrimination between 0νββ and background events have been developed. Incorporating these hardware and analysis improvements, the median 90% confidence level 0νββ half-life sensitivity after combining with the full data set acquired before the upgrade has increased twofold to 3.7×1025 yr. No statistically significant evidence for 0νββ is observed, leading to a lower limit on the 0νββ half-life of 1.8×1025 yr at the 90% confidence level.
Original language | English |
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Article number | 072701 |
Journal | Physical Review Letters |
Volume | 120 |
Issue number | 7 |
DOIs | |
State | Published - Feb 15 2018 |
Bibliographical note
Publisher Copyright:© 2018 authors. Published by the American Physical Society.
Funding
EXO-200 is supported by DOE and NSF in the U.S., NSERC in Canada, SNF in Switzerland, IBS in Korea, RFBR in Russia, DFG in Germany, and CAS and ISTCP in China. EXO-200 data analysis and simulation uses resources of the National Energy Research Scientific Computing Center (NERSC). We gratefully acknowledge the KARMEN Collaboration for supplying the cosmic-ray veto detectors, and the WIPP for their hospitality.
Funders | Funder number |
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National Science Foundation Arctic Social Science Program | 1654495 |
National Science Foundation Arctic Social Science Program | |
U.S. Department of Energy EPSCoR | |
Natural Sciences and Engineering Research Council of Canada | |
Deutsche Forschungsgemeinschaft | |
Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung | |
Russian Foundation for Basic Research | |
Chinese Academy of Sciences | |
International Science and Technology Cooperation Programme |
ASJC Scopus subject areas
- General Physics and Astronomy