Effects of nuclear surface polarization on exotic cluster radioactivity in trans-lead nuclei
Zhen Wang, Zhongzhou Ren
Abstract
Radioactive dynamics of unstable nuclei are subject to nuclear deformation. The experimentally identified cluster radioactivities in the trans-lead region are reexamined using an improved density-dependent cluster model in this work, where the role of deformation is fully taken into account. Especially, the effects of nuclear diffuseness polarization [Phys. Rev. C 88, 064327 (2013)], a nontrivial distortion of the nuclear surface due to deformation, are further investigated in the calculations of cluster radioactivity as well. In the present work, we generalize a new unified form of deformation-dependent diffuseness in the nuclear density distribution by introducing an adjustable parameter, whose sign determines the specific surface polarization mode, while its amplitude together with the deformation parameters handle the surface polarization degree of a deformed nucleus. Within this diffuseness correction, we first examine the improved model's capability of investigating the properties of cluster radioactivity. The experimental half-lives are found to be well reproduced with a factor of $\ensuremath{\approx}3$. Sequentially we consider three different surface polarization modes for the emitted cluster in the calculations and compare their impacts on the properties of cluster radioactivity. Distinct features and effects of these three surface polarization modes are presented in detail. As a result, it is found that the three different surface polarization modes may alter the geometry of daughter-cluster interactions, leading to a fluctuation of the cluster radioactivity half-lives. It is expected this work can serve as a helpful reference for both the experimental and theoretical studies of nuclear structures in the future.