Orbital and spin-polarization transfer in ionizing electron-atom collisions - art. no. 042701

We have performed an experiment in which a polarized electron beam ionizes an orbitally oriented and/or spin-polarized valence electron of sodium. The cross section for this reaction is measured for well-resolved vector momen ta of the two electrons in the final channel. In order to study the transfe r of the initial spin and orbital orientation from the electron-atom system to the final-state correlated electron pair, we develop a tensorial recoup ling scheme in which the measured quantities are expressed in terms of inde pendent, irreducible spherical tensor components. By this procedure the cro ss section is separated into terms characterized by their specific rotation al transformation properties, decoupling of geometrical effects due to init ial-state preparation from effects associated with details of the scatterin g dynamics is achieved, and exchange and orbital angular momentum transfer effects are disentangled. For a comparison with experiment we performed num erical ionization-cross section calculations within the distorted wave Born approximation and the dynamically screened three Coulomb waves theory. For some tensorial parameters significant discrepancies between theory and exp eriment are observed that underline the importance of the state-specific me asurements as stringent tests of scattering theories.