INVESTIGATION OF $Sigma$-HYPERON DECAYS. Technical Report No. 24
G. T. Condo, J. E. Crew, Richard D. Hill, Ali · OSTI OAI (U.S. Department of Energy Office of Scientific and Technical Information) · 1961
A search was made for SIGMA /sup -/ leptonic decays predicted by Feynman and Gell-Mann on the basis of a universal Fermi interaction. A stack of emulsion strips was exposed to the unenriched Berkely K/sup -/ beam. Approximately 2,300 K/sup -/ stars were found. A charged SIGMA hyperon was observed from 16.9 plus or minus 9% of all K stars. Of the 160 SIGMA /sup +/ decays, 79 were decays into a pi /sup +/ and 81 into a proton. All 75 SIGMA / sup -/ events were identified by the presence of an Auger electron. No evidence for electronic deacy of SIGMA was found. On the basis of the Feynmann and Gell- Mann prediction, two electronic decays were expected from that sample of SIGMA / sup -/ hyperons. The negative result agreed with other experiments indicating that the leptonic decay rate is appreciably below the theoretical prediction. (M.C.G.)