Alpha-Decay Study of Unfavored Transitions in Bismuth Isotopes

The unfavored α transitions of bismuth isotopes, including the newly observed α-decay fine structure in ²⁰⁹Bi Beeman et al., Phys. Rev. Lett. 108 (2012) 062501 are investigated by the generalized density-dependent cluster model (GDDCM). Instead of the Wentzel–Kramers–Brillouin barrier penetration probability, the exact solution of the Schr?dinger equation under outgoing Coulomb wave boundary conditions is presented. The calculated α-decay half-lives are found to be in good agreement with the experimental data for both odd-A and odd-odd nuclei. This indicates that the GDDCM has good applicability for unfavored α transitions in addition to favored ones. Some predictions on α-decay half-lives are also made for reference in future experiments.