Eur. Phys. J. A 16, 353-358 (2003)
DOI: 10.1140/epja/i2002-10100-3

Perturbative analysis of the decays of and

O. Civitarese¹, J. Suhonen² and H. Ejiri<sup>3, 4

1</sup>  Department of Physics, University of La Plata, C.C. 67, 1900 La Plata, Argentina
²  Department of Physics, University of Jyväskylä, P.O. Box 35, FIN-40351, Jyväskylä, Finland
³  RCNP, University of Osaka, Suita Campus, 10-1. Mihogaoka, Ibaruki, Osaka, Japan
⁴  NPL. Department of Physics, University of Washington, Seattle, WA 98195, USA

civitarese@fisica.unlp.edu.ar

(Received: 12 August 2002 / Revised version: 21 October 2002 / Published online: 18 February 2003)

Abstract
We have performed a theoretical analysis of the ground-state-to-ground-state transitions in and , based on the quasiparticle random-phase approximation and on a straightforward perturbative scheme. The results show that the single-state dominance found in the realistic calculations of the nuclear matrix elements, which is consistent with data, can be viewed as a result of the interference between few two-quasiparticle configurations.

PACS
23.40.Bw - Weak-interaction and lepton (including neutrino) aspects .
23.40.Hc - Relation with nuclear matrix elements and nuclear structure.
21.60.Jz - Hartree-Fock and random-phase approximations .
27.60.+j - .

© Società Italiana di Fisica, Springer-Verlag 2003