Tab. 1: Direct beam solar radiation measurements for selected stations in Polar regions

As part of a larger experiment, atmospheric turbidity measurements were carried out during the austral summer 1985/86 in Adelie Land, Eastern Antarctica at 1560 m elevation. A comparison of our measurements of the solar beam with those of other areas in the Arctic and Antarctic was carried out. Our values were higher than all measurements from the Arctic. For Antarctica, Plateau and Mizuho Stations, both higher in altitude, had somewhat higher values, while the value of the coastal stations were lower. We calculated also turbidity indexes such as Unke's turbidity factor T and Angstrom's turbidity coefficient ß. Mean values of T were around 2.0, which are low values indeed. Beta values were around 0.04, a rather typical value for polar regions. No trend in turbidity could be observed for the time of observation. Further, it could be shown that the decrease in intensity with increasing optical air mass was less pronounced for larger wavelengths than for shorter ones.

Discovery of τ Neutrino Appearance in the CNGS Neutrino Beam with the OPERA Experiment

The OPERA experiment was designed to search for νµ → ντ oscillations in appearance mode, i.e. by detecting the τ leptons produced in charged current ντ interactions. The experiment took data from 2008 to 2012 in the CERN Neutrinos to Gran Sasso beam. The observation of the νµ → ντ appearance, achieved with four candidate events in a subsample of the data, was previously reported. In this Letter, a fifth ντ candidate event, found in an enlarged data sample, is described. Together with a further reduction of the expected background, the candidate events detected so far allow us to assess the discovery of νµ → ντ oscillations in appearance mode with a significance larger than 5 σ.

Measurement of the νμ charged current quasielastic cross section on carbon with the T2K on-axis neutrino beam

We report a measurement of the νµ charged current quasi-elastic cross-sections on carbon in the T2K on-axis neutrino beam. The measured charged current quasi-elastic cross-sections on carbon at mean neutrino energies of 1.94 GeV and 0.93 GeV are (11.95 ± 0.19(stat.) +1.82−1.47(syst.)) ×10^−39 cm^2/neutron, and (10.64 ± 0.37(stat.)+2.03−1.65(syst.)) × 10^−39 cm^2/neutron, respectively. These results agree well with the predictions of neutrino interaction models. In addition, we investigated the effects of the nuclear model and the multi-nucleon interaction.

Limits on muon-neutrino to tau-neutrino oscillations induced by a sterile neutrino state obtained by OPERA at the CNGS beam

The OPERA experiment, exposed to the CERN to Gran Sasso νµ beam, collected data from 2008 to 2012. Four oscillated ντ Charged Current interaction candidates have been detected in appearance mode, which are consistent with νµ → ντ oscillations at the atmospheric ∆m^2 within the “standard” three-neutrino framework. In this paper, the OPERA ντ appearance results are used to derive limits on the mixing parameters of a massive sterile neutrino.

Physics potential of a long-baseline neutrino oscillation experiment using a J-PARC neutrino beam and Hyper-Kamiokande

Hyper-Kamiokande will be a next generation underground water Cherenkov detector with a total (fiducial) mass of 0.99 (0.56) million metric tons, approximately 20 (25) times larger than that of Super-Kamiokande. One of the main goals of HyperKamiokande is the study of CP asymmetry in the lepton sector using accelerator neutrino and anti-neutrino beams. In this paper, the physics potential of a long baseline neutrino experiment using the Hyper-Kamiokande detector and a neutrino beam from the J-PARC proton synchrotron is presented. The analysis uses the framework and systematic uncertainties derived from the ongoing T2K experiment. With a total exposure of 7.5 MW × 10⁷ s integrated proton beam power (corresponding to 1.56 × 10²² protons on target with a 30 GeV proton beam) to a 2.5-degree off-axis neutrino beam, it is expected that the leptonic CP phase δCP can be determined to better than 19 degrees for all possible values of δCP , and CP violation can be established with a statistical significance of more than 3 σ (5 σ) for 76% (58%) of the δCP parameter space. Using both νe appearance and νµ disappearance data, the expected 1σ uncertainty of sin²θ₂₃ is 0.015(0.006) for sin²θ₂₃ = 0.5(0.45).