Giant and pygmy dipole resonances in neutron-rich nuclei with phonon damping model

The quasiparticle representation of the phonon damping model (PDM) is developed to include the superfluid pairing correlations microscopically. The formalism is applied to calculate the photoabsorption and the electromagnetic (EM) differential cross sections of E1 excitations in neutron-rich oxygen and calcium isotopes. The present work also demonstrates that the EM differential cross section may serve as a better probe for the PDR as compared to the photoabsorption cross section because, in the former, the low-energy tail of giant dipole resonance (GDR) is enhanced thank to the photon spectral function