ANOMALOUS VIRTUAL BOUND-STATE WIDTH IN PHOTOEMISSION FROM PT IMPURITIES ON AG(110)

High-resolution angle-resolved photoemission measurements have been pe rformed on Pt impurities on a Ag(110) surface. The linewidth of the Pt 5d5/2 spin-orbit-split component near the Fermi level is observed to be twice as large as the 5d3/2 component at approximately 1 eV higher binding energy. This result is contrary to the usual expectation based on final-state lifetimes for Fermi liquids. Calculations performed wi thin the Anderson single-impurity model clearly suggest that this effe ct is mainly caused by an energy-dependent coupling between the Pt 5d state and the Ag conduction band states.