Upgrade of the T2K near detector ND280: Effect on oscillation and cross-section analysis

Abstract

The T2K neutrino oscillation experiment established the νµ → νe appearance with only 10% of the original beam request of 7.8 × 1021 30 GeV protons on target (POT). In view of the J-PARC program of upgrades of the beam intensity, the T2K-II proposal for 20 × 1021 POT aimed at establishing CP violation at 3σ level for a significant fraction of the possible δCP values. The Hyper-K proposal consists of a further increase by a factor 10 of the far detector mass. Facing the potential increase of statistics by two orders of magnitude, it is of great importance to undertake a vigorous program of near detector upgrade, with the aim of reducing the overall statistical and systematic uncertainties at the appropriate level of better than 4%. The design and performance of the proposed upgraded near-detector will be reported in these proceedings.