Precision on leptonic mixing parameters at future neutrino oscillation experiments

TL;DR

This paper compares future neutrino oscillation experiments, analyzing their precision in measuring key parameters like theta_{13} and delta, highlighting neutrino factories' superior performance and the influence of matter effects on error estimates.

Contribution

It provides a detailed comparison of proposed experiments' precision in determining neutrino mixing parameters, emphasizing the impact of matter effects and the advantages of neutrino factories.

Findings

Neutrino factories outperform other beam technologies in precision.

Maximum errors occur at CP-violating points when matter effects are small.

Ultimate precision of below 3% for theta_{13} and <7° for delta is achievable.

Abstract

We perform a comparison of the different future neutrino oscillation experiments based on the achievable precision in the determination of the fundamental parameters theta_{13} and the CP phase, delta, assuming that theta_{13} is in the range indicated by the recent Daya Bay measurement. We study the non-trivial dependence of the error on delta 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 theta_{13} and the error on delta. Neutrino factories, both high-energy or low-energy, outperform alternative beam technologies. An ultimate precision on theta_{13} below 3% and an error on delta of < 7^{\circ} at 1 sigma (1 d.o.f.) can be obtained at a neutrino factory.