Observations have been made 1570 m (water equivalent) underground with an 8000-metric-ton water Cherenkov detector. During a live time of 132 days, events consistent with the decay modes p→μ+K0 and n→νK0 were searched for in a fiducial mass of 3300 metric tons. It is concluded that the limit on the lifetime for bound plus free protons divided by the μ+K0 branching ratio is τB>2.6×1031 yr. For bound neutrons decaying into νK0 the limit is τB>0.8×1031 yr (90% confidence level).
ASJC Scopus subject areas
- Physics and Astronomy(all)