BOUND-FREE HEAVY-LEPTON PAIR PRODUCTION FOR PHOTON AND ION IMPACT ON ATOMIC-NUCLEI

Finite nuclear size is found to cause reduction in photoproduction of mu and tau pairs with bound negative lepton. The reduction is less dra matic for muons than claimed previously but very severe for experiment al production of tauonic atoms. For both types of leptons, L-shell pro duction exceeds R-shell production in heavy targets, and light targets are more favorable for ground-state tau-atom production. Implications for heavy-ion collisions are outlined.