Autoionization decay following a strong5p-hole-5d-electron interaction in fcc Yb metal

Photoemission from Yb metal reveals the existence of a strong autoionization decay above the $5p_{\frac{3}{2}}$ photoionization threshold. Intense emission at constant kinetic energy mimicking in shape the photoemission from the valence band and $4f$ states appears for photon energies larger than the $5p_{\frac{3}{2}}$ threshold. We relate this phenomenon with the atomic $5p-5d$ "giant resonance" of Yb, having a locally collapsed $5d$-screening-orbital state as an intermediate step for the autoionization.