New Results from the Daya Bay Reactor Neutrino Experiment

Abstract

This presentation describes a precision result of the neutrino mixing parameter, ${\sin }^{2}2{\theta }_{13}$, and the first direct measurement of the antineutrino mass-squared difference ${\sin }^2({\Delta }_{ee})\equiv {\cos }^2{\theta }_{12}{\sin }^2{\Delta }_{31}+{\sin }^2{\theta }_{12}{\sin }^2{\Delta }_{32}$ from the Daya Bay Reactor Neutrino Experiment. The above results are based on the six detector data-taking from 24 December 2011 to 28 July 2012. By using the observed antineutrino rate and the energy spectrum analysis, the results are ${\sin }^{2}2{\theta }_{13}=0.090_{-0.009}^{+0.008}$ and $|\Delta m_{ee}^2|=2.59_{-0.20}^{+0.19}\cdot 10^{-3}$eV${}^2$ with a ${\chi }^2$/NDF of 162.7/153. The value of $|\Delta m_{ee}^2|$ is consistent with $|\Delta m_{\mu \mu }^2|$ measured in muon neutrino beam experiments.

Comments: to appear in the proceedings of The 10th International Symposium on Cosmology and Particle Astrophysics (CosPA2013)