APPLICATION OF THE NONADIABATIC PHASE MATRIX-METHOD TO VIBRATIONAL-EXCITATION NEAR A SHORT-LIVED RESONANCE - THE CASE OF E-H-2 SCATTERING

We have applied the non-adiabatic phase matrix method for vibrational scattering processes to a system which supports an extremely broad (sh ort-lived) shape resonance. This method provides a unified, systematic treatment of the range of physical effects that influence the collisi on as the nuclear geometry varies, from strongly resonant to purely ba ckground scattering. For this implementation we have chosen the protot ypical (2)Sigma(u) shape resonance in e-H-2 scattering below 10 eV. We compare vibrational cross sections 0 --> 1 and 0 --> 2 from the prese nt non-adiabatic theory to results from fully converged body-frame vib rational close-coupling calculations and from purely adiabatic studies using the energy modified approximation.