Improved measurement of electron antineutrino disappearance at Daya Bay
Abstract
We report an improved measurement of the neutrino mixing angle θ13 from the Daya Bay Reactor Neutrino Experiment. We exclude a zero value for sin22θ13 with a significance of 7.7 standard deviations. Electron antineutrinos from six reactors of 2.9 GWth 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 sin22θ13=0.089±0.010(stat.)±0.005(syst.) in a three-neutrino framework.
- Publication:
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Chinese Physics C
- Pub Date:
- January 2013
- DOI:
- 10.1088/1674-1137/37/1/011001
- arXiv:
- arXiv:1210.6327
- Bibcode:
- 2013ChPhC..37a1001A
- Keywords:
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- High Energy Physics - Experiment;
- Nuclear Experiment
- E-Print:
- 21 pages, 24 figures. Submitted to and accepted by Chinese Physics C. Two typos were corrected. Description improved