Measuring CP violation and mass ordering in joint long baseline experiments with superbeams -: art. no. 013004

We propose to measure the CP phase delta(CP), the magnitude of the neutrino mixing matrix element \U-e3\ and the sign of the atmospheric scale mass-squared difference Deltam(31)(2) with a superbeam by the joint analysis of two different long baseline neutrino oscillation experiments. One is a long baseline experiment (LBL) at 300 km and the other is a very long baseline (VLBL) experiment at 2100 km. We take the neutrino source to be the approved high intensity proton synchrotron, HIPA. The neutrino beam for the LBL is the 2-degree off-axis superbeam, and for the VLBL a narrowband superbeam. Taking into account all possible errors, we evaluate the event rates required and the sensitivities that can be attained for the determination of delta(CP) and the sign of Deltam(31)(2). We arrive at a representative scenario for a reasonably precise probe of this part of neutrino physics.