Photoelectron angular distributions from OK shell of oriented CO molecules:: A critical comparison between theory and experiment

The dynamical information (ten dipole matrix elements and eight phase differences) has been deduced from the measured angular distributions of photoelectrons from O K shell of oriented CO molecules near the ionization threshold in the region of a sigma* shape resonance. Light polarization parallel and perpendicular to the molecular axis has been used. An important contribution of six l sigma partial waves with 0 less than or equal to l less than or equal to 5 to the sigma* shape resonance is demonstrated. A comparison with our calculations in the relaxed core Hartree-Fock approximation reveals only a qualitative agreement, therefore a more advanced theory is needed.