Single-electron capture from helium-like atomic systems by bare projectiles

The continuum-distorted-wave-Born-initial-state (CDW-BIS) approximation for the description of single-electron capture from helium-like atomic systems by completely stripped projectiles is presented. The theoretical total cross-sections for charge exchange in α-He and p-Li+ collisions are reported in the energy range 50-2000 keV/amu. We also report the results obtained by means of the continuum-distorted-wave-Born-final-state (CDW-BFS) approximation. Detailed computations for differential cross-sections are performed for p-He collisions at 500 and 200 keV. A comparison between the four-body one-channel distorted-wave approximation and three-body distorted-wave (CDW-3B) approximation is made for differential cross-sections at 200 keV. The validity of our findings is critically assessed in comparison with the available experimental data. (author)