  We report optical pumping and X-ray absorption spectroscopy experiments at
the PAL free electron laser that directly probe the electron dynamics of a
graphene monolayer adsorbed on copper in the femtosecond regime. By analyzing
the results with ab-initio theory we infer that the excitation of graphene is
dominated by indirect excitation from hot electron-hole pairs created in the
copper by the optical laser pulse. However, once the excitation is created in
graphene, its decay follows a similar path as in many previous studies of
graphene adsorbed on semiconductors, i e. rapid excitation of SCOPS (Strongly
Coupled Optical Phonons) and eventual thermalization. It is likely that the
lifetime of the hot electron-hole pairs in copper governs the lifetime of the
electronic excitation of the graphene.
