Status and perspectives of the JUNO experiment

Understand

The determination of the neutrino mass hierarchy, whether the $\nu _3$ neutrino mass eigenstate is heavier or lighter than the $\nu _1$ and $\nu _2$ mass eigenstates, is one of the remaining undetermined fundamental aspects of the Standard Model in the lepton sector.

• Furthermore the mass hierarchy determination will have an impact in the quest of the neutrino nature (Dirac or Majorana mass terms) towards the formulation of a theory of flavour.
• The Jiangmen Underground Neutrino Observatory (JUNO) is a reactor neutrino experiment under construction at Kaiping, Jiangmen in Southern China composed by a large liquid scintillator detector (sphere of 35.4 m of diameter) surronding by 18000 large PMTs and 25000 small PMTs, a water cherenkov detector and a top tracker detector.
• The large active mass (20 kton) and the unprecedented energy resolution (3\% at 1 MeV) will allow to determine the neutrino mass hierarchy with good sensitivity and to precisely measure the neutrino mixing parameters, $\theta _{12}$, $\Delta m^2_{21} $, and $\Delta m^2_{ee}$ below the 1\% level.