l-changing due to collisions by heavy particles
l-changing and n-changing collisions in the iso-sequences with heavy colliders are suspect. for an arbitrary collider what is the relationship between the collision strength and cross section for heavy colliders?
the equation in osterbrock implicitly assumes electron colliders. Burgess & Tully (2005) has useful formalism which could be applied for this situation. J. Phys. B: At. Mol. Opt. Phys. 38 (2005) 2629–2644