Measurements of the probability for 1 sσ excitation in very heavy ion-atom-collisions and determination of the binding energy of the 1 σ molecular orbital

Using particle x-ray coincidence techniques, the probability to produceK-shell vacancies in 4.7 MeV/u Pb+Z₂ (42≦Z ₂≦92) collisions for impact parametersb<100 fm was measured. For these impact parameters, the 1sσ excitation probability is greater than 1 σ 10^?2 and the 2p _1/2 σ excitation probability is greater than 1 σ 10^?1. Binding energies of the 1sσ state derived from the measured probabilities agree well with theoretical calculations.