Results from K2K

The KEK to Kamioka long baseline neutrino oscillation experiment (K2K) observed indications of neutrino oscillation in the analysis of neutrino event rate together with a distortion of the energy spectrum. Fifty-six events are observed in the Super-Kamiokande where 80.1-5.4+6.2 events are expected. Twenty-nine single ring muon type events are used to obtain the energy spectrum at Super-Kamiokande. The observed neutrino spectrum matches with the one with oscillation. The probability of no neutrino oscillation is less than 1%. In a two flavor oscillation framework, the allowed region of Δm2 and sin22≡ is obtained. For sin22≡ = 1, the allowed Δm2 region is between 1.5 x 10-3 and 3.9 x 10-3eV2 at 90% C.L. which is consistent with the values reported by the Super-Kamiokande collaboration with atmospheric neutrino observation