Single beta+-decay in 26Mg: a comparison between the shell model and quasiparticle random phase approximation

Abstract

Single beta -decay strength distributions, for beta+ transitions in 26Mg, are calculated using effective two-body interactions in the framework of the shell model and quasiparticle random phase approximation (QRPA). It is found that the QRPA, if treated in a consistent way, yields centroids for the strength distributions and predictions for the total strength, which are in good agreement with the shell model results. The detailed structure of the strength distribution, however, is different since the shell model generates more states than the QRPA. This conclusion turns out to be independent of the effective nucleon-nucleon interaction used.