Physics potential and present status of neutrino factories

The observation of atmospheric neutrinos (See, e.g., Ref.) and solar neutrinos (See, e.g., Ref.) gives the information on the mass squared differences and the mixings, which can be written in the three flavor framework of neutrino oscillations as (|∆m32|, θ23) and (∆m21, θ12), where I have adopted the standard parametrization 3 for the 3 × 3 MNSP 5,6 matrix. On the other hand, the CHOOZ result 4 tells us that |θ13| has to be small (sin 2θ13< ∼ 0.1). So the MNSP matrix looks like