title: Molecular frame photoelectron emission in the presence of autoionizing resonances.
abstract: We have measured the angular distribution of valence-shell photoelectrons excited by circularly polarized light from fixed-in-space N2O molecules, near to and on top of resonances due to Rydberg states embedded in the ionization continuum. The sign of the circular dichroism for ionization into the N2O+ (B2Pi, (1pi)-1) state is reversed on top of the lowest dominant resonances. Measured angular distributions are well predicted by state-of-the-art multichannel configuration interaction calculations. The change in sign of the circular dichroism at the peak of the resonance is the result of a rapid change in the phases of resonant dipole matrix elements by a factor of 2pi as the energy is scanned across the resonance.
authors.affiliation: Laboratoire des Collisions Atomiques et Moléculaires, LCAM, UMR Université Paris Sud et CNRS, No. 8625, Bâtiment 351, Université Paris Sud, F-91405 Orsay Cedex, France.
authors.forename: M
authors.initials: M
authors.lastname: Lebech
authors.forename: J C
authors.initials: JC
authors.lastname: Houver
authors.forename: D
authors.initials: D
authors.lastname: Dowek
authors.forename: R R
authors.initials: RR
authors.lastname: Lucchese