Lifetimes of the image-state resonances at metal surfaces

We apply the wave packet propagation approach to study electronic relaxation of excited states at surfaces. On the example of the image-state resonances on Cu(111), Ag(111), Au(111), and Be(0001) surfaces we discuss the relative role of inelastic electron-electron scattering and resonant one-electron transfer in the decay of the population of excited states. Present theoretical results are in a good agreement with available experimental data. An n(3) scaling of the resonance lifetimes with quantum number n is obtained in our study. It can be understood from the semiclassical picture for the Rydberg electron motion.