Decay channels of resonant and continuum core excitations in condensed ethylene and cyclohexane

We present Auger decay data obtained after resonant and off-resonant excitation of core holes at the carbon K edge for condensed ethylene and cyclohexane. Whereas ethylene shows a strong bound resonance below the vacuum level corresponding to the antibonding 1b_3g orbital, the lowest resonance for cyclohexane is of mixed valence/Rydberg type. The difference in spatial localization of these two adsorption resonances gives rise to very different resonant decay spectra. Whereas for ethylene strong participant channels are observed, those channels are much weaker for cyclohexane. Correspondingly, the observed spectator shifts are different for the two molecules.