Beta-delayed particle emission

Abstract

The β-decay process allows one to understand better the interactions and behaviour of the nucleons inside the nucleus. The study of nuclei at the limits of stability has recently become a central focus of nuclear structure research. The main characteristic of β-decay far from stability is the large number of decay channels open. The decay process is well understood and the interpretation of the data yields a wide variety of spectroscopic information: level energies, spins, parities, widths and level densities. In this brief paper, a summary of the progress achieved over the last few decades in the study and identification of β-delayed particle precursors is given with special emphasis on the achievements in studies of β-delayed charged particles where the detection system allowed for refined spectroscopy studies. For instance, detailed studies have been conducted on many β-delayed proton precursors of the sd shell. The comparison with the best performing shell-model calculations shows that although overall agreement is obtained in B GT distributions, the density of the observed states is higher than predicted. This points to the need to include higher order configurations in the present sd shell calculations. The extension to heavier systems is desirable. The main challenges for the present and the next decade in this domain are outlined. © 2013 The Royal Swedish Academy of Sciences.