We show through close-coupled quantum-scattering calculations that the cross section for fine-structure-changing collisions between excited ${}_{}{}^2{}_{}{}^{}$${\mathit{P}}_{3/2}$ and ground ${}_{}{}^2{}_{}{}^{}$${\mathit{S}}_{1/2}$ A atoms of the same species, where A=Rb or Cs, is very sensitive to the molecular potentials and spin-orbit matrix elements of the alkali-metal-dimer species. Spectroscopic studies of these species are needed to extract accurate parameters. New high-resolution photoassociation spectroscopy of trapped atoms could be used for this purpose.

• Received 14 June 1993

DOI:https://doi.org/10.1103/PhysRevA.49.607