Study of the high lying electric dipole excitations in Odd-A ^153–159 Eu isotopes

Abstract In this paper, we have studied the electric dipole (E1) transitions in odd-mass 153–159 Eu nuclei within Translational+Galilean Invariant Quasiparticle Phonon Nuclear Model (TGI-QPNM). Within the scope, the Giant and Pygmy Dipole Resonances (GDR and PDR) have been investigated in the energy range of 5–20 MeV. The numerical results show that the contribution of PDR and GDR to the total E1 strength is 2% and 98%, respectively. It has been found that the TGI-QPNM predicts the double hump structure and that the agreement between theoretical results and the existing experimental data is perfect, especially near the neutron binding energy S n and the first hump of the GDR. Also the comparison of the theoretical results and the existing experimental data shows reasonable agreement for the integrated moments of the cross-sections in the GDR region. We can also deduce from the structure analysis of excited states the studied isotopes, that the GDR states can be considered to be more collective than the PDR states.