Systematic study of $\alpha$ decay of nuclei around $\mathbf{Z}=82$, $\mathbf{N}=126$ shell closure within the cluster-formation model and proximity potential 1977 formalism

Abstract

In the present work, we systematically study the $\alpha$ decay preformation factors $P_{\alpha }$ within the cluster-formation model and $\alpha$ decay half-lives by the proximity potential 1977 formalism for nuclei around $Z=82$, $N=126$ closed shells. The calculations show that the realistic $P_{\alpha }$ is linearly dependent on the product of valance protons (holes) and valance neutrons (holes) $N_p{N}_n$. It is consistent with our previous works [X.-D. Sun \textit{et al.}, \href{https://journals.aps.org/prc/abstract/10.1103/PhysRevC.94.024338}{ Phys. Rev. C 94, 024338 (2016)}, J.-G. Deng \textit{et al.}, \href{https://journals.aps.org/prc/abstract/10.1103/PhysRevC.96.024318}{Phys. Rev. C 96, 024318 (2017)}], which $P_{\alpha }$ are model-dependent and extracted from the ratios of calculated $\alpha$ half-lives to experimental data. Combining with our previous works, we confirm that the valance proton-neutron interaction plays a key role in the $\alpha$ preformation for nuclei around $Z=82$, $N=126$ shell closures whether the $P_{\alpha }$ is model-dependent or microcosmic. In addition, our calculated $\alpha$ decay half-lives by using the proximity potential 1977 formalism taking $P_{\alpha }$ evaluated by the cluster-formation model can well reproduce the experimental data and significantly reduce the errors.

Comments: 4 figures, 7 tables; Accepted by Physical Review C