Systematic study of cluster radioactivity in trans-lead nuclei with various versions of proximity potential formalisms*

Abstract

In this work, based on the framework of the Coulomb and proximity potential model (CPPM), we systematically study the cluster radioactivity half-lives of 26 trans-lead nuclei by considering the cluster preformation probability which is found to possess a simple mass dependence on the emitted cluster by R. Blendowske and H. Walliser [Phys. Rev. Lett. 61, 1930(1988)]. Meanwhile, we investigate 28 different versions of the proximity potential formalisms, which \added{are the most complete known proximity potential formalisms and} have been proposed for the description of proton radioactivity, two-proton radioactivity, $\alpha$ decay, heavy-ion radioactivity, quasi-elastic scattering, fusion reactions and other applications. 
The calculated results show that the modified forms of proximity potential 1977 denoted as Prox.77-12 and the proximity potential 1981 denoted as Prox.81 are the most appropriate proximity potential formalisms for the study of cluster radioactivity as the root-mean-square deviation between experimental data and relevant theoretical results obtained are least and the both values are 0.681. For comparison, a universal decay law (UDL) proposed by Qi \textit{et al.} [Phys. Rev. C 80, 044326 (2009)], a unified formula of half-lives for $\alpha$ decay and cluster radioactivity proposed by Ni \textit{et al.} [Phys. Rev. C 78, 044310 (2008)] and a scaling law (SL) in cluster decay proposed by Horoi \textit{et al.} [J. Phys. G 30, 945 (2004)] are also used.
In addition, utilizing CPPM with Prox.77-12\added{, Prox.77-1, Prox.77-2} and Prox.81, we predict the half-lives of 51 potential cluster radioactive candidates whose cluster radioactivity is energetically allowed or observed but not yet quantified in NUBASE2020. The predicted results are in the same order of magnitude with those obtained by using the compared semi-empirical and/or empirical formulae. \added{At the same time, the competition between $\alpha$ decay and cluster radioactivity of these predicted nuclei is discussed and it is found that $\alpha$ decay predominates by comparing half-lives}