Theoretical estimate of multimuon events μ + Fe → multimuons + X

The production of charmed particles in the μ-iron Fermilab experiment at 150 GeV/c is estimated using the psi vector dominance. In order to derive the leptonic branching ratio of charmed paticles Bsub(μ) from multimuon events, the muon detection efficiency which depends on the shape of the charmed particle momentum distribution and which turns out to be low (approximately equal to 0.15 to 0.25) is computed. A good fit of the kinematical features of the multimuon events is obtained. A leptonic branching ratio of a few percent (approximately 4%) is compatible with the number of dimuons but the predicted number of trimuons is too low. Due to the very limited statistics, no firm conclusions can yet be drawn. (Auth.)