Search for Differences in Oscillation Parameters for Atmospheric   Neutrinos and Antineutrinos at Super-Kamiokande
  We present a search for differences in the oscillations of antineutrinos and neutrinos in the Super-Kamiokande -I, -II, and -III atmospheric neutrino sample. Under a two-flavor disappearance model with separate mixing parameters between neutrinos and antineutrinos, we find no evidence for a difference in oscillation parameters. Best fit antineutrino mixing is found to be at (dm2bar, sin2 2 thetabar) = (2.0x10^-3 eV^2, 1.0) and is consistent with the overall Super-K measurement. 
Super-Kamiokande Collaboration: K. Abe, Y. Hayato, T. Iida, M. Ikeda,   K. Iyogi, J. Kameda, Y. Koshio, Y. Kozuma, M. Miura,...
hep-ex