Electron- and muon-neutrino content of the atmospheric flux

Do neutrinos have mass only within matter?

“…For these parameters, nighttime regeneration can give an increase of f s in the region E <2MeV, reaching a 25%-30% increase in f s at . 4 MeV. The all-over behavior is qualitatively consistent with the survival curves for the preferred MSW models given in [16], fig.…”

“…In the lowest energy bin, p < . 4 GeV/c , the directional determination appears to be too imprecise to test the premise that only the upmoving neutrinos are changed. It is therefore worth considering the possibility that the effects depend not just on the distance but on the intervening matter as well.…”

“…The recent results on atmospheric neutrinos [1]- [4] offer a persuasive argument that neutrino mass and flavor oscillations are needed to resolve the anomalies with respect to standard model predictions. Once one accepts this conclusion, a parallel explanation of the solar neutrino deficits seems inevitable.…”

Neutrino Oscillation Experiments

“…Two decades ago, there were two neutrino disappearance anomalies: solar ν e neutrino rates were observed to be suppressed, in an energy-threshold-dependent way, in several experiments (chlorine and gallium radiochemical experiments, as well as the Kamiokande II water-Cherenkov experiment) [1]. Furthermore IMB [2] and Kamiokande II [3] had observed an energy-dependent deficit of upward-going atmospheric ν µ . Now, in both cases, these anomalies have been resolved and shown definitively to be due to neutrino oscillations.…”

A study of the water Cherenkov calorimeter

“…Water Cherenkov ring image detectors have been successfully employed in large scale experiments such as Super-Kamiokande [3], MiniBooNE [4] and IMB [5], etc. However such kind of detectors are not suitable for neutrinos with an energy more than ∼ 4GeV due to complications of showers, therefore not the choice for very long baseline neutrino oscillation experiments.…”