The electric dipole characteristics of well-deformed ^171,173Yb

Abstract

The electric dipole response of well-deformed 171,173Yb in the giant dipole resonance (GDR) and pygmy dipole resonance (PDR) range has been theoretically analyzed using the Translation and Galileo Invariant Quasiparticle Phonon Nuclear Model (TGI-QPNM). TGI-QPNM consist of an axially symmetric Woods-Saxon Potential, monopole pairing, dipole-dipole residual interaction and the restoration terms for broken translation and Galilean symmetries. Numerical calculations show the existence of considerable E1 excitations around the neutron separation threshold (Sn) in both isotopes. The existence of PDR in the 171,173Yb nucleus is discussed. The TGI-QPNM results of the photoabsorption cross-section give a double-humped shape in both nuclei, consistent with the available experimental data. The integrated moments (σ0, σ-1) and the centroid energies in the GDR region are also reproduced well.