T-matrix study of resonant reactive scattering and comparison between direct and indirect scattering contributions to the dissociative attachment process of e+AB→A+B-

A rigorous derivation of the T matrix is presented to study the effects of direct and indirect reactive scattering processes of e+AB→A+B-, involving electron(e)--molecule(AB) systems. Analysis of dissociative attachment processes e+H2→H+H- and e+HCl→H+Cl- is presented, with emphasis on the individual role of the direct and indirect processes in affecting the total cross sections. Marked differences among different electron-molecule collision systems are found from this analysis, and the cause of such differences is explained