Long-Range Excitation of Collective Modes in Mesoscopic Metal Clusters

We develop a semiclassical theory for the long range excitation of plasmon resonances in atomic clusters, based on the doorway hypothesis. The effect of the width of the plasmon resonance is fully taken into account. As an application we study plasmon excitation in small Sodium clusters, in collisions with electrons and protons.Comment: 18 pages, 4 figure