J-PARC Neutrino Beamline Upgrade Technical Design Report

Abe, K, Aihara, H, Ajmi, A, Alt, C, Andreopoulos, C ORCID: 0000-0003-2020-8215, Antonova, M, Aoki, S, Asada, Y, Ashida, Y, Atherton, A
et al (show 375 more authors) J-PARC Neutrino Beamline Upgrade Technical Design Report.

In this document, technical details of the upgrade plan of the J-PARC neutrino beamline for the extension of the T2K experiment are described. T2K has proposed to accumulate data corresponding to $2\times{}10^{22}$ protons-on-target in the next decade, aiming at an initial observation of CP violation with $3\sigma$ or higher significance in the case of maximal CP violation. Methods to increase the neutrino beam intensity, which are necessary to achieve the proposed data increase, are described.