Neutrino oscillations with a proton driver upgrade and an off-axis detector: A Case study

We study the physics capabilities of the NuMI beamline with an off-axis highly-segmented iron scintillator detector and with the inclusion of the currently under study proton driver upgrade. We focus on the prospects for the experimental determination of the remaining neutrino oscillation parameters, assuming different outcomes for experiments under way or in preparation. An optimization of the beam conditions and detector location for the detection of the nu_mu to nu_e transitions is discussed. Different physics scenarios were considered, depending on the actual solution of the solar neutrino puzzle. If KamLAND measures Delta m^2_solar, we find it possible to measure both |U_{e3}|^2 and the CP violating phase delta within a viable exposure time, assuming a realistic detector and a complete data analysis. Exposure to both neutrino and antineutrino beams is necessary. We can, in addition, shed light on Delta m^2_solar if its value is at the upper limit of KamLAND sensitivity (i.e. the precise value of Delta m^2_solar remains unknown even after KamLAND). If the solar neutrino solution is not in the LMA region, we can measure |U_{e3}|^2 and determine the neutrino mass hierarchy. The existence of the proton driver is vital for the feasibility of most of these measurements.