Coupling of the giant dipole resonance to low lying octupole modes - generator coordinate method study

The effect on the properties of low lying octupole modes of the coupling with the giant dipole resonance is studied within the Generator Coordinate Method. Results are presented for 152Sm which is deformed in its ground state and for the superdeformed state of 190Hg. A basis is first generated by Hartree-Fock+BCS calculations with constraints on the octupole and dipole moments. The same Skyrme SkM∗ effective interaction used in the mean field is then diagonalised by the GCM. For the octupole K = 0 mode, the effect of the coupling is marginal and the dipole properties of low lying states are satisfactorily described by pure octupole calculations. For the K = 1 mode, the dipole-octupole coupling slightly reduces the E1 transition strength.