Further study of alpha-decay in heavy isotopic chains considering the isospin effect

摘要

We have enhanced the deformed density-dependent cluster model to improve the quantitative description of alpha-decay in heavy even-even nuclei with 84 <= Z <= 92. To preliminarily introduce the isospin effect into alpha-decay, the neutron excess term is added in the establishment of the crucial alpha-core potential. The proton and neutron density distributions are respectively considered in different parameterized formulas by combining them with available experimental data of both the charge radius and the neutron skin thickness. The calculated alpha-decay half-lives are found to be in somewhat better agreement with the experimental data as compared with our previous results. Strikingly, it is noted that the relatively large deviation between theory and experiment, along the tail of the isotopic chain, is obviously reduced and smoother. This may indicate the necessity of considering the isospin effect in alpha-decay, especially for extremely neutron-rich nuclei, which appears to be essential for the extended study of heaviest nuclei as well.