Koike, M.Okamura, NaotoshiSaito, M.Takeuchi, Tatsu2016-10-182016-10-182006-03-011550-7998http://hdl.handle.net/10919/73282We consider a search for the CP-violating angle δ_CP in long baseline neutrino oscillation experiments. We show that the subleading δ_CP-dependent terms in the ν_µ → ν_e oscillation probability can be easily obscured by the ambiguity of the leading term which depends on |δm 2 31|. It is thus necessary to determine the value of δm₃₁² with a sufficient accuracy. The ν_µ survival events, which can be accumulated simultaneously with the ν_e appearance events, can serve for this purpose owing to its large statistics. Therefore, the combined analysis of ν_e appearance and ν_µ survival events is crucial to provide a restrictive constraint on δ_CP. Taking a test experimental setup, we demonstrate in the δ_CP -δm₃₁² plane that the analysis of ν_e appearance events leads to less restrictive constraints on the value of δ_CP due to the ambiguity of δm₃₁² and that the combined analysis efficiently improves the constraints.9 pagesenIn CopyrightAstronomy & AstrophysicsPhysics, Particles & FieldsPhysicsSOLAR-NEUTRINO OBSERVATIONSLONG-BASE-LINESUPERBEAMSOSCILLATIONSDETECTORREACTORArticle - Refereedhttps://doi.org/10.1103/PhysRevD.73.053010735