Systematic investigation of the low-energy dipole excitations in (176,178,180) Hf within rotational, translational and Galilean invariant quasiparticle RPA

Abstract

Low-energy magnetic and electric dipole excitations in the even-even isotopes I76-180Hf have been systematically studied within the rotational, translational and Galilean invariant Quasiparticle Random Phase Approximation (QRPA). The results of the calculations show that most of the states predicted to have magnetic character and the computed M1 strength in these nuclei is less strongly fragmented than in mid-shell isotopes. The results of the calculations are in good agreement with experimental data. The results of the calculations indicate the presence of a few prominent negative parity dipole K = 1 states in the energy investigated region. The comparison of the calculations with the available experimental data makes possible the interpretation of the states where parity could not be assigned experimentally. (C) 2013 Elsevier B.V. All rights reserved.