2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/99142In a high-resolution photoemission study of a Mo(110) surface state various contributions to the measured width and energy of the quasiparticle peak are investigated. Electron-phonon coupling, electron-electron interactions and scattering from defects are all identified mechanisms responsible for the finite lifetime of a valence photo-hole. The electron-phonon induced mass enhancement and rapid change of the photo-hole lifetime near the Fermi level are observed for the first time.RevTEX, 4 pages, 4 figures, to be published in PRLStrongly Correlated Electronstext