Neutrino oscillations refitted

Abstract

Here we update our previous global fit of neutrino oscillations by including the recent results which have appeared since the Neutrino-2012 conference. These include the measurements of reactor anti-neutrino disappearance reported by Daya Bay and RENO, together with latest T2K and MINOS data including both disappearance and appearance channels. We also include the revised results from the third solar phase of Super-Kamiokande, SK-III, as well as new solar results from the fourth phase of Super-Kamiokande, SK-IV. We find that the preferred global determination of the atmospheric angle $\theta_{23}$ is consistent with maximal mixing. We also determine the impact of the new data upon all the other neutrino oscillation parameters with emphasis on the increasing sensitivity to the CP phase, thanks to the interplay between accelerator and reactor data. In the appendix we present the updated results obtained after the inclusion of new reactor data presented at the Neutrino 2014 conference. We discuss their impact on the global neutrino analysis.Comment: 13 pages, 5 figures, 2 tables. An appendix providing updated results after Neutrino-2014 Conference is added. Matches published version in Physical Review

A radiative model with a naturally mild neutrino mass hierarchy

“…The resulting mass ratio probability distributions are shown in the histograms as continuous lines, however, most of the points do not correctly reproduce the correct mixing angles. We show as red histograms the mass ratio probability distributions after imposing that the mixing angles lie within the 2σ ranges derived in the latest global fit to the neutrino oscillation parameters: sin 2 θ 12 = 0.29−0.35, sin 2 θ 23 = 0.38−0.66, sin 2 θ 13 = 0.019−0.030 [17] (the global fit presented in [18] finds similar 2σ ranges for sin 2 θ 12 and sin 2 θ 13 but a significanly narrower range for sin 2 θ 23 = 0.348 − 0.448, which, nevertheless, does not affect our conclusions). Lastly, we also show for reference the experimental value of the ratio m 2 /m 3 , determined from the 2σ ranges ∆m 2 atm = (2.38 − 2.68) × 10 −3 eV 2 , It is also important to note that this mechanism to generate a mild neutrino mass hierarchy is uncorrelated to the pattern of neutrino mixing angles, as follows from the similarity of the probability distributions of the mass ratio when including or disregarding the requirement of reproducing the correct mixing angles.…”

Systematic classification of two-loop realizations of the Weinberg operator

“…Apart from the standard diagrams CLBZ [16,26,27] and PTBM [41,42] in their original incarnations (enumerated as CLBZ-1 and PTBM-1 in the following), 4 we have found a number of variations of these genuine diagrams and also several realizations of our class-II diagrams have been discussed in the literature. For example, a variant of CLBZ-1 with an additional neutral scalar vev to generate the lepton number violating triple scalar vertex h − h − k ++ has been discussed in [44,45].…”

“…However, while we do know now mass squared differences and mixing angles to a very high precision [4][5][6], there is no experimental data on whether neutrinos are Dirac or Majorana particles. From the low energy point of view Majorana neutrino masses are described by a leptonnumber-breaking dimension five effective operator, known as the Weinberg operator [7]:…”

Dark matter and lepton flavour violation in a hybrid neutrino mass model

“…We neglect small asymmetries in uncertainties and differences between the HN and IH cases as present in the recent global fits [40,41].…”