The First Results of K2K long-baseline Neutrino Oscillation Experiment

Abstract

The first results of the K2K(KEK to Kamioka) long-baseline neutrino oscillation experiment are presented in this talk. In 1999 7.2x10^18 protons on target were delivered to the experiment. During this period of running there were 3 events fully contained in the Super-Kamiokande inner detector fiducial area which occurred during the beam spill timing window. In the case of no oscillations the expected number of events during this period was 12.3+1.7-1.9. The near detectors located at KEK also have begun detailed measurements of neutrino interactions in water at around 1 GeV.