Quasiparticle-phonon model and quadrupole mixed-symmetry states of ⁹⁶Ru

¹ Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences
² Institut für Kernphysik, Technische Universität, Darmstadt
³ GSI Helmholtzzentrum für Schwerionenforschung, D-64291 Darmstadt, Germany

^a e-mail: stoyanov@inrne.bas.bg
^b e-mail: pietralla@ikp.tu-darmstadt.de

Published online: 19 January 2016

Abstract

The structure of low-lying quadrupole states of ⁹⁶Ru was calculated within the Quasiparticle-Phonon Model. It is shown that symmetric and mixed-symmetry properties manifest themselves via the structure of the excited states. The first 2⁺ state is collective and neutron and proton transition matrix elements M_n and M_p are in-phase, while the neutron and proton transition matrix elements M_n and M_p have opposite signs for the third 2⁺ state. This property of the third 2⁺ state leads to a large M1 transition between the first and third 2⁺ states. It is an unambigous demonstration of the mixed-symmetry nature of the third 2⁺ state. The structure of the first 1⁺ state is calculated. The state is a member of the two-phonon multiplet generated by the coupling of the [2₁⁺]_QRPA and the [2₂⁺]_QRPA states.