(a) Sensitivity to the neutrino mass hierarchy from Hyper Kamiokande atmospheric neutrino data. and are assumed to be known as indicated in the figure. Plot from [66]. (b) Sensitivity to the mass hierarchy at from a combination of beams at relatively short baseline with 4.4 Mt yr atmospheric neutrino data from a water Cerenkov detector. βB and SPL refer to a beta-beam and a 4 MW superbeam from CERN to Frejus (130 km), respectively, whereas T2HK corresponds to a 4 MW beam from JPARC to the HyperKamiokande detector (295 km). Dashed curves are data from beams only, and solid curves are for beams + atmospheric neutrinos. Figure is based on the results of [68].
