Scattering matrices for the examination of configuration dependences in laser-modified collisions

We examine how the theoretical analysis of configuration dependences arising from crossed-beam molecular scattering in an intense laser field can be tractably handled. Difficulties in analysing such dependences derive from dynamical equations which do not conserve the total angular momentum number J and moreover are parametrized by the total angular momentum projection quantum number M onto the field axis. We first examine simplifications which arise in the weak-field limit; for a given initial value of J we establish under broad conditions that a single weak-field close-coupling calculation suffices to determine all M dependent elements. We next extend this weak-field analysis to deal with more intense fields; essentially we intensity scale the elements from the weak-field analysis and then mix these in a new procedure for preserving unitarity in scattering matrices. Our resulting methodology is examined for a model laser-modified collision problem; results are very encouraging for utilization in realistic studies of configuration dependences.