TENSOR EFFECTS IN PYGMY DIPOLE EXCITATION

Abstract

We investigate tensor effects in pygmy dipole excitations for the case of neutron-rich nuclei Ni-68 and Sn-124 using effective nucleon nucleon Skyrme interaction. We use the Hartree-Fock-Bogoliubov (HFB) theory and employ the quasiparticle random phase approximation (ORPA). We calculate and compare the PDR and also GDR strength in the PDR, GDR energy region for QRPA calculations with and without tensor correlations. The most obvious results for the dipole excitations calculations are strongly dependent on the tensor terms. We see that the tensor correlations are more active at around 14-20 MeV, especially for the neutron-rich nuclei Ni-68. We also compare the FUR calculations with their experimental results for the different proton neutron tensor coupling constants.