Exotic α decays around the N=126 magic shell

We investigate the alpha-decay half-lives of the exotic N=125,126,127 isotones by the generalized density-dependent cluster model (GDDCM) in combination with the microscopic two-level model. The decay widths are calculated using the overlap integral of the quasibound state wave function, the scattering state wave function, and the difference of potentials, instead of using the simple semiclassical WKB method along with the Bohr-Sommerfeld quantization condition. The alpha-preformation factors are evaluated by the Z-dependent formula based on the two-level model, where the closed-shell effect is included. The calculated half-lives of alpha transitions to both ground states and excited states are found to be in good agreement with the experimental data.