The observation of the recent electron neutrino appearance in a muon neutrino beam and the high-precision measurement of the mixing angle Θ13 have led to a re-evaluation of the physics potential of the T2K long-baseline neutrino oscillation experiment. Sensitivities are explored for CP violation in neutrinos, non-maximal sin2 2Θ23, the octant of Θ23, and the mass hierarchy, in addition to the measurements of δCP, sin2 Θ23, and Δm232, for various combinations of ν-mode and ν-mode data-taking. With an exposure of 7.8 × 1021 protons-on-target, T2K can achieve 1 σ resolution of 0.050 (0.054) on sin2 Θ23 and 0.040 (0.045) × 10-3 eV2 on Δm232 for 100% (50%) neutrino beam mode running assuming sin2 Θ23 = 0.5 and Δm232 = 2.4 × 10-3 eV2. T2K will have sensitivity to the CP-violating phase δCP at 90% C.L. or better over a significant range. For example, if sin2 2Θ23 is maximal (i.e. Θ23 = 45°) the range is -115° < δCP < -60° for normal hierarchy and +50° < δCP < +130° for inverted hierarchy. When T2K data is combined with data from the NOνA experiment, the region of oscillation parameter space where there is sensitivity to observe a non-zero δCP is substantially increased compared to if each experiment is analyzed alone.
Publication Source (Journal or Book title)
Progress of Theoretical and Experimental Physics
Abe, K., Adam, J., Aihara, H., Akiri, T., Andreopoulos, C., Aoki, S., Ariga, A., Assylbekov, S., Autiero, D., Barbi, M., Barker, G., Barr, G., Bartet-Friburg, P., Bass, M., Batkiewicz, M., Bay, F., Berardi, V., Berger, B., Berkman, S., Bhadra, S., Blaszczyk, F., Blondel, A., Bojechko, C., Bordoni, S., Boyd, S., Brailsford, D., Bravar, A., & Bronner, C. (2015). Neutrino oscillation physics potential of the T2K experiment. Progress of Theoretical and Experimental Physics, 2015 (4) https://doi.org/10.1093/ptep/ptv031