摘要

The phenomenon of neutrino flavor oscillation is now well-established. Mixing among the three flavors is characterized by three mixing angles, with $\theta_{13}$ being the least well unknown angle. A precise measurement of $\theta_{13}$ can be made by utilizing a powerful nuclear reactor as the anti-neutrino source, and building “identical” near and far detectors located deep underground. An experiment at the Daya Bay nuclear power plant in South China, known as the Daya Bay Reactor (Anti)Neutrino Experiment, is among the few international collaborations aiming to do this measurement. In this talk, I will report the results from Daya Bay after a 55-days data taking since the end of last year. We have unambiguously observed the disappearance of electron anti-neutrino, leading to a determination of $\theta_{13}$.