We present a new global fit of neutrino oscillation parameters within the simplest three-neutrino picture, including new data which appeared since our previous analysis [1]. In this update we include new long-baseline neutrino data involving the antineutrino channel in T2K, as well as new data in the neutrino channel, data from NOνA, as well as new reactor data, such as the Daya Bay 1230 days electron antineutrino disappearance spectrum data and the 1500 live days prompt spectrum from RENO, as well as new Double Chooz data. We also include atmospheric neutrino data from the IceCube DeepCore and ANTARES neutrino telescopes and from Super-Kamiokande. Finally, we also update our solar oscillation analysis by including the 2055-day day/night spectrum from the fourth phase of the Super-Kamiokande experiment. With the new data we find a preference for the atmospheric angle in the upper octant for both neutrino mass orderings, with maximal mixing allowed at ∆χ 2 = 1.6 (3.2) for normal (inverted) ordering. We also obtain a strong preference for values of the CP phase δ in the range [π, 2π], excluding values close to π/2 at more than 4σ. More remarkably, our global analysis shows for the first time hints in favour of the normal mass ordering over the inverted one at more than 3σ. We discuss in detail the origin of the mass ordering, CP violation and octant sensitivities, analyzing the interplay among the different neutrino data samples. I. INTRODUCTIONThe discovery of neutrino oscillations constitutes a major milestone in astro and particle physics over the last few decades. Solar and atmospheric neutrino studies were the first to give a convincing evidence for neutrino conversion [2,3]. By studying the distortion in the neutrino spectra, laboratory experiments based at reactors and accelerators have played a key role in selecting neutrino oscillations as the conversion mechanism at work. Reactor and accelerator experiments have now brought the field of neutrino oscillations to the precision era, contributing significantly to sharpen the determination of the oscillation parameters [4][5][6][7][8][9]. Particularly relevant was the input of the KamLAND experiment in elucidating the nature of the solution to the solar neutrino puzzle [10,11]. Indeed, KamLAND measurements have ruled out alternative mechanisms involving spin flavor precession [12,13] as well as nonstandard neutrino interaction (NSI) solutions to the solar neutrino problem [14]. Such NSI-only scenarios as well as all other more exotic hypotheses are all ruled out by KamLAND [5,15]. Precision tests of the oscillation picture have already a long history, and remain as timely as ever. Indeed, one can probe neutrino NSI with atmospheric [16] as well as solar neutrino data [17, 18], where the robustness of the * https://globalfit.astroparticles.es/ † Electronic address: dvanegas@ifi.unicamp.br ‡ Electronic address: mariam@ific.uv.es § Electronic address: valle@ific.uv.es arXiv:1708.01186v2 [hep-ph] 27 Apr 2018 solar neutrino oscillation description has been question...

We present an updated global fit of neutrino oscillation data in the simplest three-neutrino framework. In the present study we include up-to-date analyses from a number of experiments. Concerning the atmospheric and solar sectors, besides the data considered previously, we give updated analyses of IceCube DeepCore and Sudbury Neutrino Observatory data, respectively. We have also included the latest electron antineutrino data collected by the Daya Bay and RENO reactor experiments, and the long-baseline T2K and NOνA measurements, as reported in the Neutrino 2020 conference. All in all, these new analyses result in more accurate measurements of θ13, θ12, $$ \Delta {m}_{21}^2 $$ Δ m 21 2 and $$ \left|\Delta {m}_{31}^2\right| $$ Δ m 31 2 . The best fit value for the atmospheric angle θ23 lies in the second octant, but first octant solutions remain allowed at ∼ 2.4σ. Regarding CP violation measurements, the preferred value of δ we obtain is 1.08π (1.58π) for normal (inverted) neutrino mass ordering. The global analysis still prefers normal neutrino mass ordering with 2.5σ statistical significance. This preference is milder than the one found in previous global analyses. These new results should be regarded as robust due to the agreement found between our Bayesian and frequentist approaches. Taking into account only oscillation data, there is a weak/moderate preference for the normal neutrino mass ordering of 2.00σ. While adding neutrinoless double beta decay from the latest Gerda, CUORE and KamLAND-Zen results barely modifies this picture, cosmological measurements raise the preference to 2.68σ within a conservative approach. A more aggressive data set combination of cosmological observations leads to a similar preference for normal with respect to inverted mass ordering, namely 2.70σ. This very same cosmological data set provides 2σ upper limits on the total neutrino mass corresponding to Σmν< 0.12 (0.15) eV in the normal (inverted) neutrino mass ordering scenario. The bounds on the neutrino mixing parameters and masses presented in this up-to-date global fit analysis include all currently available neutrino physics inputs.

We study the decoupling process of neutrinos in the early universe in the presence of three-flavour oscillations. The evolution of the neutrino spectra is found by solving the corresponding momentum-dependent kinetic equations for the neutrino density matrix, including for the first time the proper collision integrals for both diagonal and off-diagonal elements. This improved calculation modifies the evolution of the off-diagonal elements of the neutrino density matrix and changes the deviation from equilibrium of the frozen neutrino spectra. However, it does not vary the contribution of neutrinos to the cosmological energy density in the form of radiation, usually expressed in terms of the effective number of neutrinos, N eff . We find a value of N eff = 3.045, in agreement with previous theoretical calculations and consistent with the latest analysis of Planck data. This result does not depend on the ordering of neutrino masses. We also consider the effect of non-standard neutrino-electron interactions (NSI), predicted in many theoretical models where neutrinos acquire mass. For two sets of NSI parameters allowed by present data, we find that N eff can be reduced down to 3.040 or enhanced up to 3.059.