How do Neutrinos Propagate ? - Wave-Packet Treatment of Neutrino   Oscillation
  The wave-packet treatment of neutrino oscillation developed previously is extended to the case in which momentum distribution functions are taken to be a Gaussian form with both central values and dispersions depending on the mass eigenstates of the neutrinos. It is shown among other things that the velocity of the neutrino wave packets does not in general agree with what one would expect classically and that relativistic neutrinos emitted from pions nevertheless do follow, to a good approximation, the classical trajectory. 
Y.Takeuchi, Y.Tazaki, S.Y.Tsai, and T.Yamazaki