Electron-hydrogen fluoride scattering at ultralow electron energies: Possible role of dipole-supported states

Abstract

A detailed experimental and theoretical study of the interaction of very-low-energy electrons with the polar target HF is reported. This interaction is investigated experimentally by measuring rate constants for ionization and state changing in collisions between K(np) Rydberg atoms with 90\ensuremath{\lesssim}n\ensuremath{\lesssim}400 and HF. The data are analyzed using the results of rotational close-coupling calculations that include possible effects associated with dipole-supported real or virtual states. A comparison of theory and experiment suggests that low-energy-electron--HF scattering is strongly influenced by the presence of a dipole-supported virtual state with an energy, for J=0, of \ensuremath{\sim}1--1.5 meV. The present work points to the importance of dipole-supported states in electron--polar molecule scattering. \textcopyright{} 1996 The American Physical Society.