Inelastic electron-electron scattering for surface states on Cu(110) and Ag(110)

Many-body electron-electron scattering contribution to the decay rate of electron and hole excitations on the (110) surface of copper and silver is calculated within GW approximation for electron self-energy. The band structure is described using a two-dimensional model pseudopotential, which precisely reproduces the surface electronic structure at the (Y) over bar point. Combined with the previously calculated electron-phonon contribution, our result for the occupied state on Cu(110) agrees well with the available photoemission data.