Very long baseline neutrino oscillation experiments for precise measurements of mixing parameters andCPviolating 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 $\mathrm{CP}$ 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 $\mathrm{CP}$ phase ${\delta }_{\mathrm{CP}}$ and the currently unknown mixing parameter ${\theta }_{13},$ if ${\sin }^{2}2{\theta }_{13}>~0.01,$ a value $\sim 15$ times lower than the present experimental upper limit. In addition to ${\theta }_{13}$ and ${\delta }_{\mathrm{CP}},$ the experiment has great potential for precise measurements of most other parameters in the neutrino mixing matrix including $\Delta m_{32}^2,$ ${\sin }^{2}2{\theta }_{23},$ $\Delta m_{21}^2\times \sin 2{\theta }_{12},$ and the mass ordering of neutrinos through the observation of the matter effect in the ${\nu }_{\mu }\to {\nu }_e$ appearance channel.