ANALYSIS OF THE PHASE SHIFT BETWEEN \Large$\sigma$\normalsize- AND
\Large$\pi$\normalsize-CONTINUA IN THE\\
C(1s) PHOTOIONIZATION OF CO

O. Gessner, A. Hempelmann, B. Zimmermann, J. Viefhaus, R. Hentges, K.
Wieliczek, and U. Becker

Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin, Germany

Angle- and energy-resolved photoelectron-photoion-coincidence
experiments on CO at a photon energy
of \mbox{320 eV} have been performed.  Angular distributions of C(1s)
photoelectrons for fixed molecular
orientations have been measured as well as three-dimensional fragment
ion angular distributions for fixed
electron emission directions.  These distributions contain complete
information on the photoionization
process and particularly on the relative phase shift between the
outgoing $\sigma$- and $\pi$-photoelectron.