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The observation of the recent electron neutrino appearance in a muon neutrino beam and the high-precision measurement of the mixing angle Θ13 have led to a re-evaluation of the physics potential of the T2K long-baseline neutrino oscillation experiment. Sensitivities are explored for CP violation in neutrinos, non-maximal sin2 2Θ23, the octant of Θ23, and the mass hierarchy, in addition to the measurements of δCP, sin2 Θ23, and Δm232, for various combinations of ν-mode and ν-mode data-taking. With an exposure of 7.8 × 1021 protons-on-target, T2K can achieve 1 σ resolution of 0.050 (0.054) on sin2 Θ23 and 0.040 (0.045) × 10-3 eV2 on Δm232 for 100% (50%) neutrino beam mode running assuming sin2 Θ23 = 0.5 and Δm232 = 2.4 × 10-3 eV2. T2K will have sensitivity to the CP-violating phase δCP at 90% C.L. or better over a significant range. For example, if sin2 2Θ23 is maximal (i.e. Θ23 = 45°) the range is -115° < δCP < -60° for normal hierarchy and +50° < δCP < +130° for inverted hierarchy. When T2K data is combined with data from the NOνA experiment, the region of oscillation parameter space where there is sensitivity to observe a non-zero δCP is substantially increased compared to if each experiment is analyzed alone.

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Progress of Theoretical and Experimental Physics