The measurement of Neutrino Mixing Angle Theta_13 from Delayed Neutron Capture on Hydrogen at Daya Bay Reactor Anti-Neutrino Experiment
Bei-Zhen Hu1*, Zhe Wang2, Guey-Lin Lin3, Yee Hsiung1, Chung-Hsiang Wang4
1Department of Physics, National Taiwan University, Taipei, Taiwan
2Department of Engineering Physics, Tsinghua University, Beijing, China
3Institute of Physics, National Chiao Tung University, Hsinchu, Taiwan
4Department of Electro-Optical Engineering, National United University, Miaoli, Taiwan
* presenting author:Bei-Zhen Hu, email:ptbei1985@gmail.com
The Daya Bay Experiment can make an independent measurement of reactor anti-neutrino disappearance using interactions identified by neutron capture on Hydrogen (n-H). With 217 days of antineutrino data, from December 24, 2011 to July 28, 2012, the rate-only analysis for the neutron capture on hydrogen gives sin² 2θ₁₃=0.083±0.018. Several new techniques were developed to meet the challenges from the higher background and different systematics due to the lower neutron capture energy (2.2 MeV), the longer capture time (200 μs), and the larger energy loss at the detector boundary. The major systematic uncertainties are also independent from the Gd capture study. The combined Hydrogen and Gadolinium results should provide the most sensitive measurement of the neutrino mixing angle θ₁₃. More details will be shown in the presentation.


Keywords: Neutrino, theta_13, Daya Bay