Experimental limits on the nucleon lifetime for two- and three-body decay modes

Lower limits in the range of 10/sup 31/ to 10/sup 32/ yr for the partial lifetimes of a number of nucleon decay modes are obtained from a 204-live-day exposure in an 8-ktonne water Cherenkov detector (3.3 ktonne in the fiducial volume). During this period 169 contained events were observed at a rate and with characteristics consistent with expected backgrounds from atmospheric ..nu.. interactions. Nine of the contained events are compatible with either a ..nu.. interaction or nucleon decay into a number of non-..nu.. modes.