Quasiminimum Principle for Multichannel Scattering

Abstract

A new variational principle for multichannel scattering is derived which combines certain simplifying features of both Kohn and minimum principles. The rigorous bound property of the latter is relaxed slightly to gain simplifications and efficiency, especially for collisions involving particle rearrangements. The approach is essentially equivalent to treating variationally the open-channel part of the wave function, rather than solving for it exactly as required by the minimum principle. However, variations of parameters for the open and closed channels are carried out separately using a double functional.