Molecular frame photoelectron emission in the presence of autoionizing resonances.
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.
Lebech
M
M
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.
Houver
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JC
Dowek
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D
Lucchese
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