Precision on leptonic mixing parameters at future neutrino oscillation experiments

A bstractWe perform a comparison of the different future neutrino oscillation experiments based on the achievable precision in the determination of the fundamental parameters θ13 and the CP phase, δ, assuming that θ13 is in the range indicated by the recent Daya Bay measurement. We study the non-trivial dependence of the error on δ on its true value. When matter effects are small, the largest error is found at the points where CP violation is maximal, and the smallest at the CP conserving points. The situation is different when matter effects are sizable. As a result of this effect, the comparison of the physics reach of different experiments on the basis of the CP discovery potential, as usually done, can be misleading. We have compared various proposed super-beam, beta-beam and neutrino factory setups on the basis of the relative precision of θ13 and the error on δ. Neutrino factories, both high-energy or low-energy, outperform alternative beam technologies. An ultimate precision on θ13 below 3% and an error on δ of ≤ 7° at 1σ (1 d.o.f.) can be obtained at a neutrino factory.