K. Suzuki, S. Aoki, A. Ariga, T. Ariga, F. Bay, C. Bronner, A. Ereditato, M. Friend, M. Hartz, T. Hiraki, et al. Measurement of the muon beam direction and muon flux for the T2K neutrino experiment. PROGRESS OF THEORETICAL AND EXPERIMENTAL PHYSICS. 2015. 2015. 5. 053C01