Characterizing the Atmospheric Neutrino Flux

The atmospheric neutrino data of the super-Kamiokande detector were analyzed to characterize the atmospheric neutrino flux. 1) The ratio between νµ flux and νµ flux is obtained and it is consistent with existing calculations. 2) ¯ The east-west asymmetry of the atmospheric neutrino flux is also obtained for e-like and µ-like events separately. They are consistent with calculations that account for the geomagnetic field. 3) We examined possible correlations of the atmospheric neutrino events with solar activity. The data can be explained both with or without the effect of solar activity.