Excitation of multiphonon states in relativistic heavy-ion collisions

One- and two-step Coulomb excitation cross sections of the double-phonon giant dipole resonance are calculated in a semiclassical formalism. The contribution of nuclear interaction is shown to be small. The multipole sum rules are used to evaluate corresponding nuclear matrix elements; the widths of final and intermediate states are taken into account. The recent experimental data re discussed and compared to our calculations