The electromagnetic cross sections of the double giant dipole resonances (DGDR) in ${}^{136}\mathrm{Xe}$ and ${}^{208}\mathrm{Pb}$ are calculated using the strength functions obtained within the phonon damping model. The parameters of the model have been selected to describe reasonably well the single giant dipole resonance in these nuclei. The results are found in an overall agreement with the recent experimental data for the DGDR cross sections in exclusive measurements at near-relativistic energies.

• Received 21 April 2000

DOI:https://doi.org/10.1103/PhysRevLett.85.1827