Search for Leptons Produced in Association with Prompt Muons in Hadronic Interactions

We present the results of a search for leptons produced in coincidence with a prompt muon in neutron-beryllium collisions at 300 GeV/c. The experiments was sensitive to trigger muons and associated leptons of both low momentum and low transverse momentum. A clear ..mu../sup + -/..mu../sup - +/signal was found, but no significant ..mu../sup + -/e/sup - +/signal was observed. We report an upper limit for associated charmed-particle production (sigma/sub CC/ xB(C ..-->.. ..mu.. + X) x B(C ..-->.. e + x) ) of < 340 nb/nucleon, at the 95% confidence level.