Favored α -decay half-lives of odd- A and odd-odd nuclei using an improved density-dependent cluster model with anisotropic surface diffuseness

Abstract

We extend the improved density-dependent cluster model (DDCM+) of our recent work [Wang et al., Phys. Rev. C 105, 024327 (2022)] to study the favored $\ensuremath{\alpha}$ decays of odd-$A$ and odd-odd nuclei with $Z\ensuremath{\geqslant}82$. In this work, the effective $\ensuremath{\alpha}$-core interactions are determined using the double-folding potential with a realistic M3Y-Reid nucleon-nucleon interaction plus proton-proton Coulomb interaction, in which a deformation-dependent diffuseness correction is validated to address the surface anisotropy and polarization effects in nucleon density distribution. It is found that calculations within the anisotropic diffuseness would yield longer calculated $\ensuremath{\alpha}$ decay half-lives and suggest larger estimated $\ensuremath{\alpha}$-preformation factors, which is quite consistent with the conclusions obtained for the even-even $\ensuremath{\alpha}$ emitters. Meanwhile, the theoretical half-lives agree very well with the experimental data for the favored $\ensuremath{\alpha}$ decays of the odd-$A$ and odd-odd nuclei with a mean factor of 1.94 and 1.61, respectively. Remarkably, the experimental $\ensuremath{\alpha}$-decay half-life of the new thorium isotope $^{207}\mathrm{Th}$ [Yang et al., Phys. Rev. C 105, L051302 (2022)] is also well reproduced with a factor of about 2.50. Furthermore, we present the quantitative predictions on the favored $\ensuremath{\alpha}$-decay half-lives of $^{293,294}119$ and $^{294,295}120\phantom{\rule{4pt}{0ex}}\ensuremath{\alpha}$-decay chains in this work, which are expected to serve as useful references for the synthesis of new isotopes in the future.