Exact two-channel variational continuum distorted-wave theory: results for symmetric resonant exchange

Symmetric resonant charge exchange in proton-hydrogen collisions is examined theoretically using continuum distorted-wave (CDW) travelling atomic orbitals. The formulation involves a fully variational, unitary, non-perturbative calculation. The CDW wavefunctions are normalised and refined orthogonal corrections are included. Specimen-weighted impact parameter probabilities for charge exchange are presented at 25 keV and contrasted with undistorted travelling atomic-orbitals results (UTAO, also known as BMcC-TSAE). Fully variational CDW total cross sections are compared with the experimental results of McClure (1966), the non-variational CDW theoretical results of Cheshire (1964) and the fully variational UTAO theoretical results of McCarroll (1961). Differential cross sections in the centre-of-mass angle range 0 to 3.1 mrad are compared at 25 and 60 keV with the experimental results of Martin et al. (1981), the non-variational CDW theoretical results of Belkic et al. (1979) and the fully variational UTAO theoretical results of Lin.