Re-analysis of the T2KK physics potential with backgrounds

摘要

The Tokai-to-Kamioka-and-Korea (T2KK) neutrino oscillation experiment is one of the ideas to measure the neutrino mass hierarchy and the CP phase in the lepton flavor mixing matrix. We re-analyze the physics potential of the T2KK experiment by taking into account the smearing of reconstructed neutrino energy due to finite resolution of electron or muon energies, nuclear Fermi motion and resonance production, as well as the neutral current π~0 production background to the v_μ →v_e oscillation signal. It is found that the mass hierarchy pattern can still be determined at 3σ level if sin~2 2 θ_(13) ≡4|U_(e3)|~2(1-|U_(e3)|~2) >0.08 (0.09), when the hierarchy is normal (inverted) with 5 × 10~(21) POT (protons on target) exposure, for a combination of relatively large (3.0°) off-axis angle beam at Super-Kamiokande (SK) and small (0.5°) off-axis angle at 100 kton water Cerenkov detector in Korea (L = 1000 km). δ_(MNS) can still be constrained with an accuracy of =±45° (±60°) at 1 σ level for the normal (inverted) hierarchy with the above exposure when sin~2 2θ_(13) > 0.04 and δ_(MNS) = 0°. This talk is base on Ref. [1].