We report an improved measurement of the neutrino mixing angle θ_(13) from the Daya Bay Reactor Neutrino Experiment. We exclude a zero value for sin^2 θ_(13) with a significance of 7.7 standard deviations. Electron ...We report an improved measurement of the neutrino mixing angle θ_(13) from the Daya Bay Reactor Neutrino Experiment. We exclude a zero value for sin^2 θ_(13) with a significance of 7.7 standard deviations. Electron antineutrinos from six reactors of 2.9 GW_(th) were detected in six antineutrino detectors deployed in two near (flux-weighted baselines of 470 m and 576 m) and one far (1648 m) underground experimental halls. Using 139 days of data, 28909 (205308) electron antineutrino candidates were detected at the far hall (near halls). The ratio of the observed to the expected number of antineutrinos assuming no oscillations at the far hall is 0.944±0.007(stat.)±0.003(syst.). An analysis of the relative rates in six detectors finds sin^2 θ_(13) =0.089±0.010(stat.)±0.005(syst.) in a three-neutrino framework.展开更多
基金Supported by the Ministry of Science and Technology of Chinathe United States Department of Energy+15 种基金the Chinese Academy of Sciencesthe National Natural Science Foundation of Chinathe Guangdong provincial governmentthe Shenzhen municipal governmentthe China Guangdong Nuclear Power GroupShanghai Laboratory for Particle Physics and Cosmologythe Research Grants Council of the Hong Kong Special Administrative Region of ChinaUniversity Development Fund of The University of Hong Kongthe MOE program for Research of Excellence at NTU, NCTUNSC fund support from Taipeithe U.S. National Science Foundationthe Alfred P. Sloan Foundationthe Ministry of EducationYouth and Sports of the Czech Republicthe Czech Science Foundationthe Joint Institute of Nuclear Research in Dubna,Russia
文摘We report an improved measurement of the neutrino mixing angle θ_(13) from the Daya Bay Reactor Neutrino Experiment. We exclude a zero value for sin^2 θ_(13) with a significance of 7.7 standard deviations. Electron antineutrinos from six reactors of 2.9 GW_(th) were detected in six antineutrino detectors deployed in two near (flux-weighted baselines of 470 m and 576 m) and one far (1648 m) underground experimental halls. Using 139 days of data, 28909 (205308) electron antineutrino candidates were detected at the far hall (near halls). The ratio of the observed to the expected number of antineutrinos assuming no oscillations at the far hall is 0.944±0.007(stat.)±0.003(syst.). An analysis of the relative rates in six detectors finds sin^2 θ_(13) =0.089±0.010(stat.)±0.005(syst.) in a three-neutrino framework.
