Phase-integral halfway-house variational continuum distorted waves

Symmetric resonant charge transfer in proton-hydrogen collisions is examined theoretically using phase-integral halfway-house variational continuum distorted wave theory. The formulation involves the factorization of the scattering matrix into two Moller matrices, one describing the motion for - infinity or=t>or=O + . The authors use outgoing continuum distorted waves for t(O and incoming continuum distorted waves for t)O with a matching at t=O, the associated heavy particle motion remaining incoming for t(O and outgoing for t)O. Results for total cross sections are presented and compared to previous theoretical models and experimental results. Differential cross sections in the centre-of-mass range 0-3.2 mrad are presented at 25, 60 and 125 keV and are compared with the same theoretical models and previous experimental results.