Improving Hyper-Kamiokande sensitivity to CP violation with high precision near detector electron neutrino cross-section measurements

Abstract The next generation long-baseline neutrino oscillation experiment, Hyper-Kamiokande, will consist of a 260 kt underground water Cherenkov detector, placed 295 km from the source at J-PARC. This is generated by 1.3 MW proton beam striking target. In addition, suite near detectors, both on and off-axis be used. With this, Hyper-Kamiokande aims to perform precision measurements parameters governing oscillations, observation CP violation being one main experiment. To achieve these goals, require smaller systematic uncertainties than in any previous Many are related neutrino-nucleus interactions, can constrained detector close production point. For programme includes an Intermediate Water Detector, IWCD. 500 tonne located 1 able move within vertical shaft span range angles relative beam, 4 degrees. combination large target mass, precise reconstruction angle flux dependence allows for high purity statistics electron antineutrino samples. paper describes how this used constrain major uncertainty affecting measurement Hyper-Kamiokande: interaction cross section.