Updated fit to three neutrino mixing: exploring the accelerator-reactor complementarity

Abstract

We perform a combined fit to global neutrino oscillation data available as of fall 2016 in the scenario of three-neutrino oscillations and present updated allowed ranges of the six oscillation parameters. We discuss the differences arising between the consistent combination of the data samples from accelerator and reactor experiments compared to partial combinations. We quantify the confidence in the determination of the less precisely known parameters θ23, δCP, and the neutrino mass ordering by performing a Monte Carlo study of the long baseline accelerator and reactor data. We find that the sensitivity to the mass ordering and the θ23 octant is below 1σ. Maximal θ23 mixing is allowed at slightly more than 90% CL. The best fit for the CP violating phase is around 270°, CP conservation is allowed at slightly above 1σ, and values of δCP ≃ 90° are disfavored at around 99% CL for normal ordering and higher CL for inverted ordering.