Recent Results From K2K

108 observed $\nu_\mu -> \nu_\mu$ events

$150.9 {}^{+11.6}_{-10.0}$ expected events without oscillations

probability of a statistical fluctuation about $10^{-4}$

the observed spectrum reveals the type of distortion expected from oscillations


Distortion of neutrino energy spectrum observed at Super-Kamiokande (data points), compared to scaled KEK beam spectrum (black histogram), which represents expectation in the absence of neutrino oscillations. Also shown is the expected spectrum taking into account neutrino oscillation effects (red histogram), applying the K2K best-fit oscillation parameters.	Contours enclosing the 90% confidence regions for two-flavor (mu-tau) neutrino oscillation parameters (mass difference squared, and mixing parameter) for the new K2K results (green), compared to results from Super-Kamiokande atmospheric neutrino(black).