Combined Analysis of Neutrino and Antineutrino Oscillations at T2K

T2K reports its first results in the search for CP violation in neutrino oscillations using appearance and disappearance channels for neutrino- and antineutrino-mode beams. The data include all runs from January PRL 118, 151801 (2017) PHYSICAL REVIEW LETTERS week ending 14 APRIL 2017 151801-2 2010 to May 2016 and comprise 7.482 × 1020 protons on target in neutrino mode, which yielded in the far detector 32 e-like and 135 μ-like events, and 7.471 × 1020 protons on target in antineutrino mode, which yielded 4 e-like and 66 μ-like events. Reactor measurements of sin2 2θ13 have been used as an additional constraint. The one-dimensional confidence interval at 90% for the phase δCP spans the range (−3.13,−0.39) for normal mass ordering. The CP conservation hypothesis (δCP ¼ 0, π) is excluded at 90% C.L.