Projectile angular distribution in single electron capture from helium by fast protons

Abstract

In addition to the Thomas peak, occurs at 0.47 mrad, another peak has been observed at ≈ 0.75 mrad in a recent measurement for projectile angular differential cross sections of single electron capture in proton-helium collision at impact energies of MeV region [M. Gudmundsson et al., J. Phys. B 43, 185209 (2010)]. Stimulated by this report, the differential cross section is calculated based on the first Born approximation for single ionization of helium by proton impact. Calculations with and without inter-electron correlation give almost the same results, and the peak observed experimentally near 0.75 mrad is not accounted for in the treatment.