Electronic symmetry assignments for the ArXe and KrXe band systems in the vicinity of the resonance line

Mass-resolved two-photon ionization spectra of ArXe and KrXe have been recorded using both linearly and circularly polarized fundamental laser beams. From the resultant intensity changes, the published excited-state electronic symmetry assignments for the band systems of ArXe in the region of the resonance line are confirmed, while those for KrXe are shown to be incorrect. The spectroscopic constants of the newly assigned KrXe transition in this region can be understood if the adiabatic excited state involved is an admixture of diabatic states that dissociate to and .