KAMIOKA nucleon decay experiment

Summary Recent results of KAMIOKA nucleon decay experiment are presented. The great majority, ∼95%, of the contained events can be naturally explained as due to the atmospheric neutrinos,i.e. the rate and the momentum distribution of the pseudoelastic ν_μ and ν_e events and the multiplicity distribution. However, 5 multiple-ring events remain each defying this interpretation at 90% c.l. Stringent flux upper limits are obtained for magnetic monopole from the searches for Rubakov effect in the detector and in the Sun. KAMIOKANDE collaboration:K. Arisaka, T. Kajita, T. Kifune, M. Koshiba, K. Miyano, M. Nakahata, Y. Oyama, T. Suda, A. Suzuki, K. Takahashi, M. Takita andY. Totsuka: ICEPP and Department of Physics, University of Tokyo; Institute of Cosmic Ray Research, University of Tokyo; KEK, National Laboratory for High Energy Physics and Department of Physics, Niigata University. (As of January 1985,K. Arisaka moved to Department of Physics, Pennsilvania University.)