JUNO experiment: detector status and physics opportunities

The Jiangmen Underground Neutrino Observatory (JUNO) is a multi-purpose neutrino experiment currently under construction in South China. The detector consists of a 35.4 m diameter acrylic sphere filled with 20 000 t of ultra-pure liquid scintillator and makes JUNO the largest liquid scintillator-based, underground neutrino observatory capable of addressing many important topics in different fields of neutrino physics. The primary goal of JUNO is to determine the neutrino mass ordering with a significance greater than 3 − 4σ after six years of data taking and to perform high-precision measurement of neutrino oscillation parameters. This will be achieved by exploiting the electron antineutrinos emitted by the Yangjiang and Taishan nuclear power plants located about 53 km away from the experimental site, together with the precise measurement of the reactor antineutrino energy spectrum provided by its satellite detector, the Taishan Antineutrino Observatory, located at about 30 m from a reactor core of the Taishan plant. The JUNO central detector will be equipped with 17612 20-inch and 25600 3-inch photomultiplier tubes to provide a photocathode coverage of 78% and an energy resolution better than 3% at 1 MeV with an absolute energy scale uncertainty lower than 1%. The central detector hall will be filled with ultra-pure water to shield the environmental radioactivity and act as a water Cherenkov detector for cosmic muons tagging. Thanks to its excellent characteristics in terms of an unprecedented active mass and excellent energy resolution, the extensive physics program of JUNO comprises also solar neutrinos, atmospheric neutrinos, supernova neutrinos, and geo-neutrinos, as well as beyond Standard Model physics topics such as nucleon decay. The detector construction is expected to be completed in 2024. In this paper I review the current status of the detector and the physics topics covered by JUNO.