Measurement of single production in neutral current neutrino interactions with water by a 1.3 GeV wide band muon neutrino beam

Neutral current single π0 production induced by neutrinos with a mean energy of 1.3 GeV is measured using a 1000 ton water Cherenkov detector in the K2K long baseline neutrino experiment. The cross section for this process relative to the total charged current cross section is measured to be 0.064±0.001(stat.)±0.007(sys.). The momentum distribution of neutral current π0s from a water target is measured with high statistics for the first time.