Anharmonic Properties of the Double Giant Dipole Resonance

A systematic microscopic study of the anharmonic properties of the double giant dipole resonance (DGDR) has been carried out, for the first time, for nuclei with mass number $A$ spanning the whole mass table. It is concluded that the corrections of the energy centroid of the $J^{\pi }{=0\mathrm{}}^{+}$ and $2^{+}$ components of the DGDR from its harmonic limit are negative, have a value of the order of a few hundred keV, and follow an $A^{-1\mathrm{}}$ dependence.