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