The standard three-neutrino (3ν) oscillation framework is being increasingly refined by results coming from different sets of experiments, using neutrinos from solar, atmospheric, accelerator and reactor sources. At present, each of the known oscillation parameters [the two squared mass gaps (δm 2 , ∆m 2 ) and the three mixing angles (θ12, θ13, θ23)] is dominantly determined by a single class of experiments. Conversely, the unknown parameters [the mass hierarchy, the θ23 octant and the CP-violating phase δ] can be currently constrained only through a combined analysis of various (eventually all) classes of experiments. In the light of recent new results coming from reactor and accelerator experiments, and of their interplay with solar and atmospheric data, we update the estimated N σ ranges of the known 3ν parameters, and revisit the status of the unknown ones. Concerning the hierarchy, no significant difference emerges between normal and inverted mass ordering. A slight overall preference is found for θ23 in the first octant and for nonzero CP violation with sin δ < 0; however, for both parameters, such preference exceeds 1σ only for normal hierarchy. We also discuss the correlations and stability of the oscillation parameters within different combinations of data sets.

We perform a global analysis of neutrino oscillation data, including high-precision measurements of the neutrino mixing angle θ13 at reactor experiments, which have confirmed previous indications in favor of θ13 > 0. Recent data presented at the Neutrino 2012 Conference are also included. We focus on the correlations between θ13 and the mixing angle θ23, as well as between θ13 and the neutrino CP-violation phase δ. We find interesting indications for θ23 < π/4 and possible hints for δ ∼ π, with no significant difference between normal and inverted mass hierarchy.

Within the standard three-neutrino framework, the absolute neutrino masses and their ordering (either normal, NO, or inverted, IO) are currently unknown. However, the combination of current data coming from oscillation experiments, neutrinoless double beta (0νββ) decay searches, and cosmological surveys, can provide interesting constraints for such unknowns in the sub-eV mass range, down to O(10 −1 ) eV in some cases. We discuss current limits on absolute neutrino mass observables by performing a global data analysis, that includes the latest results from oscillation experiments, 0νββ decay bounds from the KamLAND-Zen experiment, and constraints from representative combinations of Planck measurements and other cosmological data sets. In general, NO appears to be somewhat favored with respect to IO at the level of ∼ 2σ, mainly by neutrino oscillation data (especially atmospheric), corroborated by cosmological data in some cases. Detailed constraints are obtained via the χ 2 method, by expanding the parameter space either around separate minima in NO and IO, or around the absolute minimum in any ordering. Implications for upcoming oscillation and non-oscillation neutrino experiments, including β-decay searches, are also discussed.

It is shown that the results of the Super-Kamiokande atmospheric neutrino experiment, interpreted in terms of nu(mu)<-->nu(tau) flavor transitions, can probe possible decoherence effects induced by new physics (e.g., by quantum gravity) with high sensitivity, supplementing current laboratory tests based on kaon oscillations and on neutron interferometry. By varying the (unknown) energy dependence of such effects, one can either obtain strong limits on their amplitude or use them to find an unconventional solution to the atmospheric nu anomaly based solely on decoherence.

We present a comprehensive phenomenological analysis of a vast amount of data from neutrino flavor oscillation and non-oscillation searches, performed within the standard scenario with three massive and mixed neutrinos, and with particular attention to subleading effects. The detailed results discussed in this review represent a state-of-the-art, accurate and up-to-date (as of August 2005) estimate of the three-neutrino mass-mixing parameters.Comment: Final version (including a new Appendix), to be published in "Progress in Particle and Nuclear Physics". Higher-resolution pdf file and eps figures can be download from http://www.ba.infn.it/~now2004/PPNP_review