Solar and Atmospheric Neutrino Results from Super-Kamiokande

K2K is a long baseline neutrino oscillation experiment using a neutrino beam produced at the KEK 12 GeV PS, a near detector complex at KEK and a far detector (Super-Kamiokande) in Kamioka, Japan. The experiment was constructed and is being operated by an international consortium of institutions from Japan, Korea, and the US. The experiment started taking data in 1999 and has successfully taken data for about two years. K2K is the first long beseline neutrino oscillation experiment with a baseline of order hundreds of km and is the first accelerator based neutrino oscillation experiment that is sensitive to the Super-Kamiokande allowed region obtained from the atmospheric neutrino oscillation analysis. A total of 44 events have been observed in the far detector during the period of June 1999 to April 2001 corresponding to 3.85 × 1019 protons on target. The observation is consistent with the neutrino oscillation expectations based on the oscillation parameters derived from the atmospheric neutrinos, and the probability that this is a statistical fluctuation of non-oscillation expectation of [Formula: see text] is less than 3%.

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Interpreting the atmospheric neutrino anomaly

Physics Letters B ◽

10.1016/s0370-2693(98)01021-1 ◽

1998 ◽

Vol 439 (1-2) ◽

pp. 123-129 ◽

Cited By ~ 31

Author(s):

R.P. Thun ◽

S. McKee

Keyword(s):

Atmospheric Neutrino

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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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