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Title: New measurement of θ 13 via neutron capture on hydrogen at Daya Bay

This article reports an improved independent measurement of neutrino mixing angle θ 13 at the Daya Bay Reactor Neutrino Experiment. Electron antineutrinos were identified by inverse β-decays with the emitted neutron captured by hydrogen, yielding a data set with principally distinct uncertainties from that with neutrons captured by gadolinium. With the final two of eight antineutrino detectors installed, this study used 621 days of data including the previously reported 217-day data set with six detectors. The dominant statistical uncertainty was reduced by 49%. Intensive studies of the cosmogenic muon-induced 9Li and fast neutron backgrounds and the neutron-capture energy selection efficiency, resulted in a reduction of the systematic uncertainty by 26%. The deficit in the detected number of antineutrinos at the far detectors relative to the expected number based on the near detectors yielded sin 213 = 0.071 ± 0.011 in the three-neutrino-oscillation framework. As a result, the combination of this result with the gadolinium-capture result is also reported.
Publication Date:
Report Number(s):
Journal ID: ISSN 2470-0010; PRVDAQ; R&D Project: PO-022; KA2201020
Grant/Contract Number:
SC0012704; AC02-05CH11231
Accepted Manuscript
Journal Name:
Physical Review D
Additional Journal Information:
Journal Volume: 93; Journal Issue: 7; Journal ID: ISSN 2470-0010
American Physical Society (APS)
Research Org:
Brookhaven National Laboratory (BNL), Upton, NY (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
Contributing Orgs:
Daya Bay Collaboration
Country of Publication:
United States
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; neutrino oscillation; hydrogen neutron-capture; reactor antineutrinos; Daya Bay
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1249657; OSTI ID: 1456938