2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/28577The anomalous plasmon linewidth dispersion (PLD) measured in K by vom Felde, Sprosser-Prou, and Fink (Phys. Rev. B 40, 10181 (1989)), has been attributed to strong dynamical electron-electron correlations. On the basis of ab initio response calculations, and detailed comparison with experiment, we show that the PLD of K is, in fact, dominated by decay into particle-hole excitations involving empty states of d-symmetry. For Li, we shed new light on the physics of the PLD. Our all-electron results illustrate the importance of ab initio methods for the study of electronic excitations.14 pages, 4 figures, for html version of the paper, see http://web.utk.edu/~weiku/research/Materials ScienceStrongly Correlated Electronstext