The influence of giant resonances on the production of δ-electrons in heavy ion collisions
Recently measuredδ-electron spectra from elastic U + Pd-collisions at 6.1 MeV/u show for small impact parameters enhancements up to two orders of magnitude relative to coupled-channel calculations which describeδ-electron production for larger impact parameters almost perfectly. If these deviations are interpreted as due to modified nuclear trajectories they imply most interesting structures of the internuclear potential at the Coulomb-barrier. We show that an alternative explanation, namely anδ-electron enhancement due to strong collective nuclear excitations, e.g. giant resonances, does not reproduce the experimental finding.