Title: Studies of Non-Standard Effects in Atmospheric Neutrino Oscillations
Speaker: Wei Wang, Boston University, 8 Feb 2007

Abstract: Mass-induced oscillations between muon neutrinos and tau neutrinos
have become the standard theory accounting for the zenith angle distribution of atmospheric neutrinos. However,
there are other models which are able to produce similar effects and they are of both theoretical and experimental
interest. In this talk, a neutrino oscillation analysis between muon neutrinos and tau neutrinos is first presented
using the Super-Kamiokande atmospheric neutrino data. Then, this standard oscillation is compared with three
categories of non-standard models: 1. oscillations between muon neutrinos and sterile neutrinos; 2. neutrino
oscillations induced by violations of Lorentz invariance and CPT symmetry; 3. vanishing muon neutrinos caused by
neutrino decoherence and neutrino decay. The minimum chi-square values of these different models are compared and
it is found that the standard oscillation model fits the atmospheric neutrino observation better than non-standard ones
significantly. Based on this, we are able to limit the allowable contributions of these non-standard effects.