Electron correlations in single-electron capture from heliumlike atomic systems

Total cross sections for single-electron transfer from two selected heliumlike atomic systems by bare projectiles are computed by means of the four-body continuum distorted-wave approximation. The effect of dynamic electron correlations is explicitly taken into account through the complete perturbation potentials. Specifically, we consider the symmetric ${\mathrm{He}}^{2+}-\mathrm{H}\mathrm{e}$ and asymmetric ${\mathrm{H}}^{+}{-\mathrm{L}\mathrm{i}}^{+}$ collisions in a large energy range from 50 to 10 000 keV. With regard to a previous work of Belkić et al. [Phys. Rev. A 56, 3675 (1997)], where a major influence of electronic correlations on single-electron capture by fast protons in helium was found, the present paper expands the study to higher projectile $\left({\mathrm{He}}^{2+}\right)$ and target $\left({\mathrm{Li}}^{+}\right)$ nuclear charges, with the purpose of determining whether electronic correlations remain important. The prior and post total cross sections are found to be in satisfactory agreement with the available experimental data.