Carbon K-shell Photo Ionization of CO: Molecular frame angular   Distributions of normal and conjugate shakeup Satellites
  We have measured the molecular frame angular distributions of photoelectrons emitted from the Carbon K shell of fixed-in-space CO molecules for the case of simultaneous excitation of the remaining molecular ion. Normal and conjugate shake up states are observed. Photo electrons belonging to normal \Sigma -satellite lines show an angular distribution resembling that observed for the main photoline at the same electron energy. Surprisingly a similar shape is found for conjugate shake up states with \Pi -symmetry. In our data we identify shake rather than electron scattering (PEVE) as the mechanism producing the conjugate lines. The angular distributions clearly show the presence of a \Sigma -shape resonance for all of the satellite lines. 
T. Jahnke, J. Titze, L. Foucar, R. Wallauer, T. Osipov, E. P. Benis,   O. Jagutzki, W. Arnold, A. Czasch, A. Staudte, M. Sch...
physics.atom-ph