T2K reports its first results in the search for CP violation in neutrino oscillations using appearance and disappearance channels for neutrino- and antineutrino-mode beam. The data include all runs from Jan 2010 to May 2016 and comprise
T2K Collaboration, " ,protons on target in neutrino mode, which yielded in the far detector 32 e-like and 135 -like events, and ,protons on target in antineutrino mode which yielded 4 e-like and 66 -like events. Reactor measurements of have been used as an additional constraint. The one-dimensional confidence interval at 90% for spans the range ( , ) for normal mass ordering. The CP conservation hypothesis ( ) is excluded at 90% C.L.First combined analysis of neutrino and antineutrino oscillations at T2K" (January 2, 2017).
The study is also notable for how much of a needle in a haystack enterprise neutrino physics is with an immense number of protons on target in neutrino or anti-neutrino mode (10^21) producing just 237 measurable events.