Revisiting giant photoelectron asymmetries in fenchone enantiomers

We report a joint experimental and theoretical study of core ionization of fenchone enantiomers at photon energies in the range 294.9–306.9 eV. Our experimental method enables the measurement of photoelectron momentum distributions with full 4 π solid-angle coverage in the laboratory frame, yielding photon-energy-resolved dichroic and anisotropy parameters for photoelectrons emitted from C 1 s ( C = O and C – H n ) orbitals. Our experimental results are supported by electronic-structure calculations and agree fairly well with values available in the literature. Our findings demonstrate that core-level photoelectron circular dichroism is highly sensitive to both the localization of the emitting orbital and the treatment of background contributions, providing a solid basis for future studies of complex chiral molecules.