Binary--single-star scattering VII. Hard Binary Exchange Cross Sections   for Arbitrary Mass Ratios: Numerical Results and Semi-Analytic Fits
  We present the first comprehensive fitting formula for exchange reactions of arbitrary mass ratios. In a comparison with numerical results, this expression is shown to be accurate in the hard binary limit to within 25\% for most mass ratios. The result will be useful in forming quantitative estimates for the branching ratios of various exchange reactions in astrophysical applications. For example, it can be used to construct quantitative formation scenarios for unusual objects in globular clusters, such as binaries containing a pulsar. 
D.C. Heggie, P. Hut and S.L.W. McMillan