Workshop outline

  Atmospheric neutrino experiments have been studying νμ→ντ oscillations extensively. The zenith angle and energy dependent deficit, or more recently the L/E dependent deficit, of atmospheric muon neutrinos has been used to constrain the neutrino oscillation parameters: sin223>0.9 and 1.9<Δm232<3.0x10-3 eV2.

  As a natural extension of the present νμ→ντ oscillation studies, atmospheric neutrino experiments should study three flavor oscillation effects. One is the effects driven by θ13 and the other is the ones driven by the solar oscillation terms (θ12 and Δm122). Especially, thanks to the diameter of the Earth, atmospheric neutrino experiments are, in principle, sensitive to the solar neutrino oscillation terms. If the solar neutrino oscillation effect is observed, it is possible to get unique information, such as a discrimination of θ23 larger or smaller than 45degree for non-maximal sin223.

  It is predicted that the effect of solar neutrino oscillations on atmospheric neutrino experiments is relatively a small effect, and improvements of the accuracy of our understanding of the flux and the neutrino interaction cross sections are required. In addition, very careful evaluations of the systematic uncertainties are required. These topics will be discussed in detail in this workshop.