Quasiparticle band structure of Na and simple metals

We have made absolute measurement of the quasiparticle band structure of Na(110) using angle-resolved photoemission. These data show that the occupied band is parabolic but with an 18% narrowing in bandwidth compared to self-consistent band calculations. A simple model calculation of the self-energy correction for a homogeneous electron gas produces good agreement with the data, if a dielectric response beyond the random-phase approximation is included. Experiment and theory are compared for other simple metals.