Friction effects in excitation to high vibrational states of the electronic ground state of carbon dioxide via the 4 eV shape resonance

Conventional electron energy-loss spectra and two-dimensional electron scattering spectra are presented with unusual features. These features are accounted for by considering the trapping of the wave-packet due to a quantum mechanical analogue of friction. A detailed analysis of the spectra is given in terms of the vibrational eigenfunctions and eigen-energies of the available decay channels. This analysis supports the suggestion of a frictional mechanism. Such a mechanism could be quite general for polyatomic molecules, giving a new way to study non-Markovian aspects of the Schrödinger equation.