In a counter experiment at the LBL Bevatron, we have searched for the process K + -p+vi;v and have found no evidence for its existence. We have recorded ten events which could be examples of this decay mode, but could also be examples of K + -p+vy in which the y was not detected. Treating these as unidentified events and assuming the p f spectrum proposed by Bardin, Bilenky, and Pontecorvo, we obtain a decay rate T(K + -p+ vVv) 6 X 10-6r(K + + all) (90% confidence level).The data are presented in such a way as to allow calculation of rates for any assumed spectrum. The experiment provides a test for higher-order weak processes and sets constraints on certain first-order models.

The first hypernuclei production experiment using a beam of heavy ions from the Lawrence Berkeley Laboratory Bevatron is described. Mass 16 hypernuclei were produced by 2.1 GeV/ nucleon 0 ions incident on a polyethylene target. These relativistic hypernuclei were studied with large gap spark chambers that were electronically triggered by the low momenturn K' meson produced in association. Analysis of 22 events yields a mean lifetime 7( +) = (0. 86+0'&3&) x 10 sec.NUCLEAR REACTIONS Hypernuclei ( 0, NA or OA) E+, E =2.1 GeV/nucleon, polyethylene target, 0'~roughly measured; mean lifetime of mass 16 hypernuclei measured.

In a counter experiment a t the Lawrence Berkeley Laboratory Bevatron we have searched for the process K t -ntvP in the kinetic energy interval 60 < T,< 105 MeV and have found no examples of this decay mode. Combining our data with those of Klems, Hildebrand, and Stiening for the interval 117