Neutrino Oscillations and the Anomalous Atmospheric Neutrino Flux

In this letter we show that the evidence for neutrino oscillations from the super-Kamiokande atmospheric neutrino data fully determines the 3×3 neutrino-oscillations mixing matrix and predicts an energy-independent solar neutrino deficit at the level of 45%. This corresponds to a ratio of measured to predicted neutrino flux of [Formula: see text], in good agreement with the experimental results. We achieve this result within the framework of a minimal, three-generation neutrino mixing, with mass squared differences of ΔM2≃0.45 eV 2 and [Formula: see text]. The mixing matrix derived here is characterized by the mixing angles θ=35.1°, β=5.5° and ψ=23.3°, and a vanishing CP-violating phase, δ=0.

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Atmospheric neutrino event rates: the expectations

Philosophical Transactions of the Royal Society of London Series A Physical and Engineering Sciences ◽

10.1098/rsta.1994.0008 ◽

1994 ◽

Vol 346 (1678) ◽

pp. 75-84 ◽

Cited By ~ 4

Keyword(s):

Precise Measurement ◽

Neutrino Oscillations ◽

Detection Efficiency ◽

Atmospheric Neutrino ◽

Neutrino Flux ◽

New Physics ◽

Naturally Occurring ◽

Deep Underground ◽

Many Sources ◽

Event Rates

Naturally occurring energetic neutrinos produced by interactions of cosmic rays in the atmosphere produce a signal in deep underground detectors which is a convolution of neutrino flux, neutrino cross section and detection efficiency. The predicted ratio of events induced by v e as compared to v μ is relatively robust (because many sources of uncertainty cancel in the ratio), but it differs significantly from what is observed. Interpretations that involve new physics (e.g. neutrino oscillations or nucleon decay) have been proposed. One interpretation in terms of neutrino oscillations would imply a low value of neutrino-induced upward muons. Although there is no strong evidence for such a deficit, uncertainties in calculating the expected absolute rate prevent one from eliminating this interpretation at present. Precise measurement of muon fluxes at high altitude, as well as calibration of detectors with neutrino beams from accelerators, will help clarify the situation.

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Theory Predictions for Inclusive atmospheric Neutrino flux

EPJ Web of Conferences ◽

10.1051/epjconf/20135209002 ◽

2013 ◽

Vol 52 ◽

pp. 09002

Author(s):

Morihiro Honda

Keyword(s):

Atmospheric Neutrino ◽

Neutrino Flux

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NEUTRINO OSCILLATIONS AND THE EXACT PARITY MODEL

Modern Physics Letters A ◽

10.1142/s0217732394000186 ◽

1994 ◽

Vol 09 (02) ◽

pp. 169-179 ◽

Cited By ~ 62

Author(s):

R. FOOT

Keyword(s):

Neutrino Mass ◽

General Result ◽

Neutrino Oscillations ◽

Mass Matrix ◽

Atmospheric Neutrino ◽

Solar Neutrinos ◽

Specific Model ◽

Neutrino Mixing ◽

Mixing Angles ◽

Significant Deficit

We re-examine neutrino oscillations in exact parity models. Previously it was shown in a specific model that large neutrino mixing angles result. We show here that this is a general result of neutrino mixing in exact parity models provided that the neutrino mass matrix is real. In this case, the effects of neutrino mixing in exact parity models is such that the probability of a given weak eigenstate remaining in that eigenstate averages to less than half when averaged over many oscillations. This result is interesting in view of the accumulating evidence for a significant deficit in the number of solar neutrinos. It may also be of relevance to the atmospheric neutrino anomaly.

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