Daya Bay and Jiangmen Underground Neutrino Observatory (JUNO)neutrino experiments

Abstract

Neutrino Physics is one of the most active branches in particle physics. Many puzzles remain in neutrinos, which may lead to new physics beyond the Standard Model of particle physics. We summarize the status and major scientific problems in neutrino physics, and introduce the neutrino program in China, with details on the on-going Daya Bay Neutrino Experiment and the being-built Jiangmen Underground Neutrino Observatory (JUNO). Daya Bay discovered a new type of neutrino oscillation in 2012 and measured the corresponding neutrino mixing angle <italic>q</italic>₁₃, by detecting reactor neutrinos. In this paper, we introduce the physics background and the project background of Daya Bay, summarize the experimental method and design principles, and describe the detector design and construction. Many new ideas and technical innovations have been implemented in the detector design and construction, thus a 0.2% relative uncertainty from detector is achieved. In the next decades, the Daya Bay results will be the most precise measurement on this fundamental parameter. JUNO was proposed in 2008 and formally approved in 2013. It will determine the neutrino mass hierarchy and precisely measure three neutrino mixing parameters by detecting reactor neutrinos at a distance of 53 km. With a 20 kton liquid scintillator detector of 3% energy resolution, JUNO will also be promising in studying supernovae neutrino, solar neutrino, geo-neutrino, atmospheric neutrino, as well as other exotic searches. It will be a multiple-purpose experimental platform for many world-leading researches. We introduce the progress on the experiment design and detector R&D. Besides Daya Bay and JUNO, we extend the neutrino studies by joining the neutrinoless double beta decay experiment EXO, and by starting R&D of MOMENT, a new idea to produce accelerator neutrino beam.