Lack of M-preserving propensities in rotationally inelastic collisions of NO(X 2Π1/2)

Abstract

An expansion of the collision‐frame scattering amplitude for JM→J′M′ transitions in irreducible tensor components facilitates the investigation of M‐preserving propensities when quantization refers to the geometric or kinetic apse vectors. Specifically one can demonstrate that M preservation can be expected for processes where backward scattering dominates, but not for transitions which are forward peaked. For forward scattered processes involving open‐shell diatomics, either even or odd changes in M (apse quantization) will be dominant, depending on the e/f symmetry label of the initial and final wave functions. These formal results will be illustrated by close‐coupling calculations on collisions of NO(X ²Π_1/2).