Born approximation for collisional alignment

It is shown that the first order Born approximation is in qualitative agreement with many of the experimental observations on the angular momentum alignment of Na2 molecules produced during collisions with He. A model for certain aspects of the second order Born approximation is introduced which is able to predict the observed deviation of the orientation of the alignment from being directed along the kinematic apse. As well, exact expressions for the alignment cross section are given in terms of reduced T-matrix elements.