Complex Kohn variational principle for the solution of Lippmann-Schwinger equations (Q1206587)

The use of the Kohn variational principle has been restricted in scattering calculations since the corresponding \(K\) matrix exhibits anomalous singularities. Various authors have suggested that this problem can be avoided by choosing complex boundary conditions and in the space spanned by the complex trial function \((E-H)^{-1}\) does not present anomalous singularities. This paper uses this technique for the first time to the study of nucleon-nucleon scattering. An alternative derivation of the complex Kohn variational principle is given and both analytic and numerical solutions are given for various potentials.