CPNonconservation in Three-Neutrino Oscillations

Direct CP tests in neutrino oscillations require comparison of off-diagonal channels ν_α→ν_β with CP-conjugate channels ν_α→ν_β (or with ν_β→ν_α by assuming CPT invariance). For the three-neutrino case, it is shown that CP-nonconservation effects are identical in all three available channels νₑ↔ν_μ, ν_μ↔ν_τ, and ν_τ↔νₑ, and argued that they could be large and measurable in meson factory experiments. Indirect CP tests include the correlation of average probabilities.