Systematic Approximations for the Single-Channel Scattering Amplitude
F. Coester · Physical Review · 1964
The scattering amplitude for two-particle single-channel scattering may be computed by inverting a Hilbert-space operator $1\ensuremath{-}K$, where $K$ is compleely continuous and depends on the real energy as a parameter. This inversion can always be accomplished by obtaining a finite number of eigenvalues and eigen-functions of $K$ together with a modified Born expansion which is guaranteed to converge. Another method consists in the inversion of a finite matrix, the elements of which are computed by a convergent perturbation series.