High intensity neutrino oscillation facilities in Europe

The EUROnu project has studied three possible options for future, high intensity neutrino oscillationfacilities in Europe. The first is a Super Beam, in which the neutrinoscome from the decay of pions created by bombarding targets with a 4 MW proton beam from the CERN High Power Superconducting Proton Linac. The far detector for this facility is the 500 kt MEMPHYSwater Cherenkov, located in the Frejus tunnel. The second facility is the Neutrino Factory, in which the neutrinoscome from the decay of μ+ and μ- beams in a storage ring. The far detector in this case is a 100 kt magnetized iron neutrino detectorat a baseline of 2000 km. The third option is a Beta Beam, in which the neutrinoscome from the decay of beta emitting isotopes, in particular 6He and 18Ne, also stored in a ring. The far detector is also the MEMPHYSdetector in the Frejus tunnel. EUROnu has undertaken conceptual designs of these facilities and studied the performance of the detectors. Based on this, it has determined the physics reach of each facility, in particular for the measurement of CP violation in the lepton sector, and estimated the cost of construction. These have demonstrated that the best facility to build is the Neutrino Factory. However, if a powerful proton driver is constructed for another purpose or if the MEMPHYSdetector is built for astroparticle physics, the Super Beam also becomes very attractive.