Eur. Phys. J. A (2005) 25: 531-534
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

Abstract

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.