Our herein described combined analysis of the latest neutrino oscillation data presented at the Neutrino2020 conference shows that previous hints for the neutrino mass ordering have significantly decreased, and normal ordering (NO) is favored only at the 1.6σ level. Combined with the χ² map provided by Super-Kamiokande for their atmospheric neutrino data analysis the hint for NO is at 2.7σ. The CP conserving value δ_CP = 180° is within 0.6σ of the global best fit point. Only if we restrict to inverted mass ordering, CP violation is favored at the ∼ 3σ level. We discuss the origin of these results — which are driven by the new data from the T2K and NOvA long-baseline experiments —, and the relevance of the LBL-reactor oscillation frequency complementarity. The previous 2.2σ tension in ∆m²₂₁ preferred by KamLAND and solar experiments is also reduced to the 1.1σ level after the inclusion of the latest Super-Kamiokande solar neutrino results. Finally we present updated allowed ranges for the oscillation parameters and for the leptonic Jarlskog determinant from the global analysis.

We present the results of a global analysis of the neutrino oscillation data available as of fall 2018 in the framework of three massive mixed neutrinos with the goal at determining the ranges of allowed values for the six relevant parameters. We describe the complementarity and quantify the tensions among the results of the different data samples contributing to the determination of each parameter. We also show how those vary when combining our global likelihood with the χ ² map provided by Super-Kamiokande for their atmospheric neutrino data analysis in the same framework. The best fit of the analysis is for the normal mass ordering with inverted ordering being disfavoured with a Δχ ² = 4.7 (9.3) without (with) SK-atm. We find a preference for the second octant of θ ₂₃, disfavouring the first octant with Δχ ² = 4.4 (6.0) without (with) SK-atm. The best fit for the complex phase is δ _CP = 215° with CP conservation being allowed at Δχ ² = 1.5 (1.8). As a byproduct we quantify the correlated ranges for the laboratory observables sensitive to the absolute neutrino mass scale in beta decay, $$ {m}_{\nu_e} $$ m ν e , and neutrino-less double beta decay, m _ee , and the total mass of the neutrinos, Σ, which is most relevant in Cosmology.

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, δ_CP, 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 δ_CP ≃ 90° are disfavored at around 99% CL for normal ordering and higher CL for inverted ordering.

We present an updated global analysis of neutrino oscillation data as of September 2024. The parameters θ ₁₂, θ ₁₃, $$ \Delta {m}_{21}^2 $$ ∆ m 21 2 , and $$ \mid \Delta {m}_{3\ell}^2\mid $$ ∣ ∆ m 3 ℓ 2 ∣ (ℓ = 1, 2) are well-determined with relative precision at 3σ of about 13%, 8%, 15%, and 6%, respectively. The third mixing angle θ ₂₃ still suffers from the octant ambiguity, with no clear indication of whether it is larger or smaller than 45 ^° . The determination of the leptonic CP phase δ _CP depends on the neutrino mass ordering: for normal ordering the global fit is consistent with CP conservation within 1σ, whereas for inverted ordering CP-violating values of δ _CP around 270° are favored against CP conservation at more than 3.6σ. While the present data has in principle 2.5–3σ sensitivity to the neutrino mass ordering, there are different tendencies in the global data that reduce the discrimination power: T2K and NOvA appearance data individually favor normal ordering, but they are more consistent with each other for inverted ordering. Conversely, the joint determination of $$ \mid \Delta {m}_{3\ell}^2\mid $$ ∣ ∆ m 3 ℓ 2 ∣ from global disappearance data prefers normal ordering. Altogether, the global fit including long-baseline, reactor and IceCube atmospheric data results into an almost equally good fit for both orderings. Only when the χ ² table for atmospheric neutrino data from Super-Kamiokande is added to our χ ², the global fit prefers normal ordering with ∆χ ² = 6.1. We provide also updated ranges and correlations for the effective parameters sensitive to the absolute neutrino mass from β-decay, neutrinoless double-beta decay, and cosmology.

Neutrino oscillations involving eV-scale neutrino mass states are investigated in the context of global neutrino oscillation data including short and long-baseline accelerator, reactor, and radioactive source experiments, as well as atmospheric and solar neutrinos. We consider sterile neutrino mass schemes involving one or two mass-squared differences at the eV² scale denoted by 3+1, 3+2, and 1+3+1. We discuss the hints for eV-scale neutrinos from $ \mathop{{{v_e}}}\limits^{{\left( - \right)}} $ disappearance (reactor and Gallium anomalies) and $ \mathop{{{v_{\mu }}}}\limits^{{\left( - \right)}}\to \mathop{{{v_e}}}\limits^{{\left( - \right)}} $ appearance (LSND and MiniBooNE) searches, and we present constraints on sterile neutrino mixing from $ \mathop{{{v_{\mu }}}}\limits^{{\left( - \right)}} $ and neutral-current disappearance data. An explanation of all hints in terms of oscillations suffers from severe tension between appearance and disappearance data. The best compatibility is obtained in the 1+3+1 scheme with a p-value of 0.2% and exceedingly worse compatibilities in the 3+1 and 3+2 schemes.