Improved double-folding α -nucleus potential by including nuclear medium effects

Abstract

The nuclear medium effect in $\ensuremath{\alpha}$ decay is introduced into the microscopic double-folding model to construct an improved $\ensuremath{\alpha}$-nucleus potential. Under the local density approximation, the $\ensuremath{\alpha}$-cluster density distribution is considered to vary with the surrounding matter density as a result of the medium effect. The density-dependence of the $\ensuremath{\alpha}$ cluster is incorporated by the width parameter of the Gaussian function and constrained by the critical features derived from previous microscopic studies. The influence of the medium effect to the geometry of the $\ensuremath{\alpha}$-nucleus potential is studied by comparing with the conventional double-folding potential. To examine the improved potential, the $\ensuremath{\alpha}$-decay half-lives and preformation factors of even-even spherical nuclei are calculated and compared with experimental data. With the $\ensuremath{\alpha}$-decay data being well explained, it is concluded that the inclusion of the nuclear medium effect contributes to an improved double-folding $\ensuremath{\alpha}$-nucleus potential, which incorporates more details of the $\ensuremath{\alpha}$-decay process.