Shell closure effects studied via cluster decay in heavy nuclei

Abstract

The effects of a shell closure in nuclei via cluster decay have been investigated. In this context, we used the preformed cluster model (PCM) of Gupta and collaborators based on quantum-mechanical fragmentation theory. The key point in the cluster radioactivity is that it involves the interplay of close shell effects of parent and daughter nuclei. Small half-life for a parent indicates the shell stabilized daughter and long half-life indicates the stability of the parent against the decay. In the cluster decay of trans-lead nuclei observed so far, the end product is doubly magic lead for its neighboring nuclei. We have extended the idea of cluster radioactivity. We have investigated the decay of different nuclei where zirconium is taken as a daughter nucleus, which is a very well-known deformed shell closure nucleus. The branching ratios of cluster decay and α-decay have also been studied for various nuclei, leading to magic or almost doubly magic daughter nuclei. The calculated cluster decay half-lives are in well agreement with the observed data. For the first time a possibility of cluster decay of 218U nucleus is predicted.