Status of JUNO experiment

Abstract

JUNO is an experiment conceived primarily to study neutrino oscillations. It is composed by 20 kton of high purity liquid scintillator, read-out by a dual system: the large PMT system (LPMT), 17612 20-inch photomultipliers, and the small PMTs (SPMT), 25600 3-inch photomultipliers. The experiment is also endowed with a Water Cherenkonv Veto and a Top Tracker, made by scintillator strips, to control the background due to cosmic rays. The design of the experiment has been performed in order to reach an unprecedented energy resolution of 3% at 1 MeV, needed to infer the neutrino mass hierarchy from the spectrum measurement of the electron anti-neutrinos produced by two nuclear power plants and observed at a baseline of about 50 km. The large mass, together with the performances of its detectors, will allow JUNO to precisely measure at sub-percent level several oscillation parameters ($θ_{12}$ , $Δm^2_{21}$, $Δm^2_{31}$). JUNO will be also an excellent observatory for solar, atmospheric, SuperNova and geo-neutrinos. Other exotic researches, such as the proton decay, will also be made. To improve the neutrino mass hierarchy measurement, recently the collaboration approved the construction of a reference detector, TAO (Taishan Anti-neutrino Observatory), at a short baseline (30 m) from one of the rector cores. The TAO detector will also be based on the liquid scintillator technology, with the light read-out by SiPM (Silicon Photomultipliers) in order to improve the energy resolution. In this presentation the experiment design will be presented and the installation status reported. In addition the physics reach of the experiment will also be discussed.