INTERPLAY BETWEEN SINGLE-PARTICLE AND COLLECTIVE DEGREES OF FREEDOM IN THE EXCITATION OF THE LOW-LYING STATES IN CE-140

Differential cross sections for electron scattering from Ce-140 have been measured for excitation energies less than 3.3 MeV over a range of effective momentum transfer of 0.4 to 3.1 fm-1. The data have been analyzed to extract transition charge densities. These densities are interpreted in terms of a quasiparticle-phonon model and self-consistent finite Fermi system theory to disentangle the collective and noncollective modes of excitation.