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.

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 discuss in detail solar neutrino oscillations with \delta m^2/E in the range [10^-10,10^-7] eV^2/MeV. In this range, which interpolates smoothly between the so-called ``just-so'' and ``Mikheyev-Smirnov-Wolfenstein'' oscillation regimes, neutrino flavor transitions are increasingly affected by matter effects as \delta m^2/E increases. As a consequence, the usual vacuum approximation has to be improved through the matter-induced corrections, leading to a ``quasi-vacuum'' oscillation regime. We perform accurate numerical calculations of such corrections, using both the true solar density profile and its exponential approximation. Matter effects are shown to be somewhat overestimated in the latter case. We also discuss the role of Earth crossing and of energy smearing. Prescriptions are given to implement the leading corrections in the quasi-vacuum oscillation range. Finally, the results are applied to a global analysis of solar nu data in a three-flavor framework.Comment: 17 pages (RevTeX) + 8 figures (PostScript). Final version, to appear in Phys. Rev.

Within the standard 3ν mass-mixing framework, we present an up-to-date global analysis of neutrino oscillation data (as of January 2016), including the latest available results from experiments with atmospheric neutrinos (Super-Kamiokande and IceCube DeepCore), at accelerators (first T2K ν and NOνA ν runs in both appearance and disappearance mode), and at short-baseline reactors (Daya Bay and RENO far/near spectral ratios), as well as a reanalysis of older KamLAND data in the light of the "bump" feature recently observed in reactor spectra. We discuss improved constraints on the five known oscillation parameters (δm 2 , |∆m 2 |, sin 2 θ 12 , sin 2 θ 13 , sin 2 θ 23 ), and the status of the three remaining unknown parameters: the mass hierarchy [sign(±∆m 2 )], the θ 23 octant [sign(sin 2 θ 23 − 1/2)], and the possible CP-violating phase δ. With respect to previous global fits, we find that the reanalysis of KamLAND data induces a slight decrease of both δm 2 and sin 2 θ 12 , while the latest accelerator and atmospheric data induce a slight increase of |∆m 2 |. Concerning the unknown parameters, we confirm the previous intriguing preference for negative values of sin δ (with best-fit values around sin δ −0.9), but we find no statistically significant indication about the θ 23 octant or the mass hierarchy (normal or inverted). Assuming an alternative (so-called LEM) analysis of NOνA data, some δ ranges can be excluded at > 3σ, and the normal mass hierarchy appears to be slightly favored at ∼ 90% C.L. We also describe in detail the covariances of selected pairs of oscillation parameters. Finally, we briefly discuss the implications of the above results on the three non-oscillation observables sensitive to the (unknown) absolute ν mass scale: the sum of ν masses Σ (in cosmology), the effective ν e mass m β (in beta decay), and the effective Majorana mass m ββ (in neutrinoless double beta decay).