Theory of Collisionally Induced Intramultiplet Mixing in Excited Alkali Atoms

Abstract

The theory of intramultiplet mixing in ${}^{2}P$ resonance excited states of alkali atoms induced by collisions with noble gas atoms is discussed in connection with various mechanisms of nonadiabatic coupling between molecular states. The semiclassical approach is used, and a high value of the Massey parameter corresponding to $\frac{1}{2}\to \frac{3}{2}$ transitions is assumed. Two coupling regions are found, and it is shown that the main contribution to the total inelastic cross sections for heavy partners is given by the Coriolis interaction at small interatomic distances. Comparison between theory and experiment reveals reasonable agreement. In addition, the validity of the perturbation theory for almost adiabatic collisions is discussed.