Semiclassical picture of depolarizing collisions: Application to collisional studies using laser spectroscopy

An extension of the Jeffreys-Wentzel-Kramers-Brillouin approximation to inelastic processes is used to obtain the scattering amplitude which describes the collisionally induced depolarization of magnetic substate coherences. It is found that the scattering amplitudes contain contributions from two overlapping regions. For large interatomic separations, the different Zeeman sublevels are shifted and mixed by collisions, but follow a common collision trajectory. For small interatomic separations, it is possible to find adiabatic eigenstates which follow distinct collision trajectories. The theory is used to investigate the nature of the depolarizing collision kernels and rates which enter into the analysis of laser spectroscopy experiments.