The conversion probability and emission ratio of charged Sigma - hyperons following K/sup -/ meson capture at rest in carbon

A study has been made of K/sup -/ meson interactions at rest in the CERN 1.1 m/sup 3/ heavy liquid bubble chamber filled with a mixture of hydrocarbons. The data are used to determine (i) the internal conversion probability, C( Sigma /sup -/), of Sigma /sup -/ hyperons produced in association with pi /sup +/ mesons by K/sup -/ meson interactions in carbon nuclei, (ii) the relative emission frequencies of ( Sigma /sup +/ pi /sup +/) and ( Sigma /sup -/ pi /sup +/) pairs, E( Sigma /sup +/ pi /sup +// Sigma /sup -/ pi /sup +/), and the emission frequency E( Sigma /sup +or-/ pi /sup -or+//K/sup -/), of ( Sigma /sup +or-/ pi /sup -or+/) pairs per K/sup -/ meson absorption in carbon, (iii) the branching fraction, P( Sigma /sup -/ pi /sup +//K /sup -/), for the primary process K/sup -/+p to Sigma /sup -/+ pi /sup +/ in carbon and (iv) the trapping probability, T( Lambda /sup 0/), for Lambda /sup 0/ hyperons produced by Sigma /sup -/ hyperon interactions in carbon nuclei. (26 refs)

K/sup -/-meson absorptions at rest in carbon nuclei leading to final states containing a Lambda -hyperon

A study has been made of K/sup -/-meson interactions at rest in the CERN 1.1 m/sup 3/ heavy-liquid bubble chamber filled with a mixture of hydrocarbons. The emission frequency of Lambda /sup 0/-hyperons following K/sup -/-meson absorptions in carbon nuclei is determined to be 0.68+or-0.02. A detailed study of the ( Lambda /sup 0/ pi /sup -/) final state has allowed an estimate to be made of the internal- conversion probability C( Sigma /sup +/) of Sigma /sup +/-hyperons produced in association with pi /sup -/-mesons. The result is C( Sigma /sup +/)=0.62+or-0.02. The contribution of the direct channel to the ( Lambda /sup 0/ pi /sup -/) final state is found to be 0.23+or-0.01. The results are compared with those obtained for other absorbing media. (27 refs)

Experimental study of the reaction nu p to mu /sup -/p pi /sup +/ (Gargamelle neutrino propane experiment)

A sample of 357 events fitting the reaction nu +p to mu /sup -/+p+ pi /sup +/ on free proton is obtained from the Gargamelle neutrino propane experiment at the CERN-PS. The average value of the cross section above 1 GeV is found to be (0.60+or-0.07)10/sup -38/ cm/sup 2 /. The reaction is dominated by the production of the Delta /sup ++ /(1232) resonance. Results on the Delta /sup ++/ spin density matrix are given. (13 refs)