ICARUS+NESSiE: A proposal for short baseline neutrino anomalies with innovative LAr imaging detectors coupled with large muon spectrometers

The proposal for an experimental search for sterile neutrinos beyond the Standard Model with a new CERN-SPS neutrino beam is presented. The experiment is based on two identical LAr-TPC@?s followed by magnetized spectrometers, observing the electron and muon neutrino events at 1600 and 300 m from the proton target. This project will exploit the ICARUS T600, moved from LNGS to the CERN ''Far'' position. An additional 1/4 of the T600 detector will be constructed and located in the ''Near'' position. Two spectrometers will be placed downstream of the two LAr-TPC detectors to greatly complement the physics capabilities. Comparing the two detectors, in absence of oscillations, all cross sections and experimental biases cancel out. Any difference of the event distributions at the locations of the two detectors might be attributed to the possible existence of @n-oscillations, presumably due to additional neutrinos with a mixing angle sin^2(2@q_n_e_w) and a larger mass difference @Dm_n_e_w^2. The superior quality of the LAr imaging TPC, in particular its unique electron-@p_0 discrimination allows full rejection of backgrounds and offers a lossless @n_e detection capability. The determination of the muon charge with the spectrometers allows the full separation of @n_@m from anti-@n_@m and therefore controlling systematics from muon mis-identification largely at high momenta.