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

Abstract. Non-linear effects on supernova neutrino oscillations, associated with neutrino-neutrino interactions, are known to induce collective flavor transformations near the supernova core for θ 13 = 0. In scenarios with very shallow electron density profiles, these transformations have been shown to couple with ordinary matter effects, jointly producing spectral distortions both in normal and inverted hierarchy. In this work we consider a complementary scenario, characterized by higher electron density, as indicated by shock-wave simulations during a few seconds after bounce. In this case, early collective flavor transitions are decoupled from later, ordinary matter effects. Moreover, such transitions become more amenable to both numerical computations and analytical interpretations in inverted hierarchy, while they basically vanish in normal hierarchy. We numerically evolve the neutrino density matrix in the region relevant for self-interaction effects, using thermal spectra and a representative value sin 2 θ 13 = 10 −4 . In the approximation of averaged intersection angle between neutrino trajectories, our simulations neatly show the collective phenomena of synchronization, bipolar oscillations, and spectral split, with analytically understandable features, as recently discussed in the literature. In the more realistic (but computationally demanding) case of non-averaged neutrino trajectories, our simulations do not show new significant qualitative features, apart from the smearing of "fine structures" such as bipolar nutations. Our results seem to suggest that, at least for non-shallow matter density profiles, averaging over neutrino trajectories plays a minor role in the final outcome. In this case, the swap of ν e and ν µ,τ spectra above a critical energy may represent an unmistakable signature of the inverted neutrino hierarchy, especially for θ 13 small enough to render further (ordinary or even turbulent) matter effects irrelevant.PACS numbers: 14.60. Pq, 13.15.+g, 97.60.Bw Collective neutrino flavor transitions in supernovae and the role of trajectory averaging 2

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).

We present an up-to-date global analysis of data coming from neutrino oscillation and nonoscillation experiments, as available in April 2018, within the standard framework including three massive and mixed neutrinos. We discuss in detail the status of the three-neutrino (3ν) mass-mixing parameters, both known and unknown. Concerning the latter, we find that: normal ordering (NO) is favored over inverted ordering (IO) at 3σ level; the Dirac CP phase is constrained within ∼ 15% (∼ 9%) uncertainty in NO (IO) around nearly-maximal CP-violating values; the octant of the largest mixing angle and the absolute neutrino masses remain undetermined. We briefly comment on other unknowns related to theoretical and experimental uncertainties (within 3ν) or possible new states and interactions (beyond 3ν).