https://doi.org/10.1140/epjad/i2005-06-057-5
ENAM 2004
Self-consistent relativistic QRPA studies of soft modes and spin-isospin resonances in unstable nuclei
1
Institut für Kernphysik, Technische Universität Darmstadt, Schlossgartenstrasse 9, D-64289, Darmstadt, Germany
2
Physics Department, Faculty of Science, University of Zagreb, Croatia
3
Institute for Nuclear Theory, University of Washington, WA, 98195, Seattle, USA
4
Physik-Department der Technischen Universität München, D-85748, Garching, Germany
* e-mail: nils.paar@physik.tu-darmstadt.de
Received:
14
October
2004
Accepted:
18
February
2005
Published online:
6
May
2005
The excitation phenomena in unstable nuclei are investigated in the framework of the relativistic quasiparticle random-phase approximation (RQRPA) in the relativistic Hartree-Bogoliubov model (RHB) which is extended to include effective interactions with explicit density-dependent meson-nucleon couplings. The properties of the pygmy dipole resonance (PDR) are examined in 132Sn and within isotopic chains, showing that already at moderate proton-neutron asymmetry the PDR peak energy is located above the neutron emission threshold. A method is suggested for determining the size of the neutron skin within an isotopic chain, based on the measurement of the excitation energies of the Gamow-Teller resonance relative to the isobaric analog state. In addition, for the first time the relativistic RHB + RQRPA model, with tensor ω meson-nucleon couplings, is employed in calculations of β-decay half-lives of nuclei of the relevance for the r-process.
PACS: 21.60.Jz Hartree-Fock and random-phase approximations – / 21.30.Fe Forces in hadronic systems and effective interactions – / 24.10.Jv Relativistic models –
© Società Italiana di Fisica and Springer-Verlag, 2005