Answers are grounded in this paper and cite their sources.
Exact numerical calculations for 1s-1s electron capture by protons on hydrogen show that the second Born approximation is characterised by a peak in the differential cross section at theta cm =0.054 degrees when the projectile energy is above 5 MeV. Below 5 MeV this peak disappears. Between 3 and 1000 MeV the total non-relativistic cross section in the second-order Brinkman-Kramers (BK) approximation lies below the first-order BK total cross section.
No takes yet. Share an insight, caveat, or question.
Simony et al. (1981) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: