Very long baseline neutrino oscillation experiments for precise measurements of mixing parameters and CP violating effects

We analyze the prospects of a feasible, Brookhaven National Laboratory based, very long baseline neutrino oscillation experiment consisting of a conventional horn produced low energy wideband beam and a detector of 500 kton fiducial mass with modest requirements on event recognition and resolution. Such an experiment is intended primarily to determine CP violating effects in the neutrino sector for 3-generation mixing. We analyze the sensitivity of such an experiment. We conclude that this experiment will allow determination of the CP phase δ_CP and the currently unknown mixing parameter θ₁₃, if sin²2θ₁₃⩾0.01, a value ∼15 times lower than the present experimental upper limit. In addition to θ₁₃ and δ_CP, the experiment has great potential for precise measurements of most other parameters in the neutrino mixing matrix including Δm²₃₂, sin²2θ₂₃, Δm²₂₁×sin 2θ₁₂, and the mass ordering of neutrinos through the observation of the matter effect in the ν_μ→ν_e appearance channel.