Vibrationally resolved partial cross sections and asymmetry parameters for oxygen K-shell photoionization of the CO2 molecule

O K-shell photoionization of the CO2 molecule causes antisymmetric vibrations v '(3) in the core-ionized molecule. The v '(3)-resolved partial cross sections sigma(+)(v ' 3) and asymmetry parameters beta(v ' 3) are measured in the Sigma(u) shape resonance region above the O K-shell ionization threshold of the CO2 molecule. Neither the shape resonance energy in sigma(+)(v ' 3) nor the value of beta(v ' 3) shows v '(3)- dependence. This v '(3)- independent nature is attributed to the fact that v '(3) vibrations do not cause any change of the size of the potential box responsible for the formation of the shape resonance. Multiple scattering calculations employing the v '(3)-dependent fixed-nuclei approximation reproduce well the measured v '(3)-resolved partial cross sections.