Hyper-K is a successor project to Super-K with the capability of making definitive measurements of the main outstanding questions in oscillation physics: CP-violation, mass hierarchy and the θ 23 octant. The detector will also have a world leading sensitivity to nucleon decay and the observation of cosmic origin neutrinos. The experiment will operate in the same beamline as T2K with the same off-axis configuration. The Hyper-K detector baseline design (pictured below) will be a third generation water Cherenkov detector in Kamioka with a 1.0 (0.56) Mt total (fiducial) mass - making it 20 (25) times larger than Super-K.
Based on an exposure of 7.5 MW x 107 sec, and assuming the mass hierarchy is known and sin2 2θ13=0.1, the expected CP-violation coverage is illustrated in the plot below: a 3σ (5 σ) measurement can be made for 76% (58%) of all CP-phase values.