Revisiting T2KK and T2KO physics potential and – beam ratioKaoru Hagiwara, Pyungwon Ko, Naotoshi Okamura and Yoshitaro TakaesuEur. Phys. J. C, 77 3 (2017) 138DOI: https://doi.org/10.1140/epjc/s10052-017-4684-1