Significant improvement of half-life calculation of α decays by considering the nuclear medium effect

Abstract

We incorporate the nuclear medium effect into α-decay calculation through a reformulation of the conventional double-folding model. The improved model enables the α cluster to simultaneously change its size at different nuclear density during the Coulomb penetration process, thus reflecting the effect from the variation of nuclear mean field and Pauli blocking at the nuclear surface. To evaluate the result of such a dynamic effect, we perform a systematic calculation of α-decay half-lives for even-even α-emitters within a deformed cluster model. We found that the medium effect optimises the shape of α-nucleus potential at the surface region, leading to a remarkable reduction in the deviations between the theoretical and experimental decay rates. The result implies the importance of the dynamic aspect of α clustering in describing a realistic α-nucleus interaction. Keywords: α decay, Half-life, Nuclear medium effect, α clustering, α-preformation factor