Recherche de la production de particules charmées dans un faisceau de neutrinos

Typical topologies of the production of charmed particles are searched in a sample of 50000 neutrino interactions. The heavy liquid bubble chamber Gargamelle set up was used in the CERN neutrino beam, with energies of 1 to 10 GeV. 3 events of the type $\nu + N \to \mu^- e^+ \Lambda^0$ + ... and 18 events of the type $\nu + N \to \mu^- e^+$ ...were found. It is very unlikely that all these events are due to ordinary background sources. The analysis, in the same sample, of the strange particles production suggests an apparent violation of the $\Delta$S = $\Delta$Q rule. Interpreted in terms of charmed baryon production, these results allow the estimate of its leptonic branching ratio