Intermediate-velocity atomic collisions. V. Electron capture and loss in ${\mathrm{C}}^{3+}$ and ${\mathrm{O}}^{5+}$ collisions with ${\mathrm{H}}_2$ and He

Electron-capture and -loss cross sections in ${\mathrm{C}}^{3+}$ and ${\mathrm{O}}^{5+}$ collisions with ${\mathrm{H}}_2$ and He are measured in the 1.5- to 4.0-MeV energy range. The results for projectile electron loss are compared with the plane-wave Born approximation including the interaction between target and projectile electrons. It is shown that such single-channel analysis is not sufficient to explain the results, but that projectile electron loss, electron capture by the projectile, and target ionization must be considered together to interpret the data. This interpretation allows one to extract the electron-capture probability at small impact parameters. A theoretical estimate based on the independent-particle model and the decay model to unitarize the electron-capture and target-ionization probabilities is described. This analysis explains the main features of the cross sections involved as well as the electron-capture probability at small impact parameters.