The nuclear surface diffuseness effects on the alpha decay of heavy and super heavy nuclei

Abstract

We select 300 different parent nuclei in the range Z from 64 to 106. The proximity potentials Zhang 2013 and Guo 2013 are employed to calculate the nuclear potential. The influence of the nuclear surface diffuseness is applied in the calculations of interaction potential between the emitted alpha particle and daughter nucleus through the reduced radius parameter. The systematic analysis of the radial behavior of interaction potential with and without the surface diffuseness effect reveals that these effects play decisive role in the calculation of nucleus-nucleus potential at the touching radius of the two interacting nuclei. We indicate that its influence decreases outside the touching configuration. In addition, our results reveal that the barrier penetration probability of the alpha particle through the barrier decreases by imposing the mentioned physical effects. It is worth noting that the calculated alpha-decay half-lives using the Zhang 2013 and Guo 2013 proximity potentials accompanied by the surface effects agree very well with the available experimental data. The theoretical halflives are calculated for 50 super-heavy nuclei using the modified forms of the Zhang 2013 and Guo 2013 models. The comparison with available experimental data and also with different empirical formulas demonstrates that the Guo 2013 model is suitable to deal with the alpha decay half-lives of SHN. Then the predictions of alpha decay half-lives for 65 SHN with Z from 120 to 126 are made by using Guo 2013 model with the surface effects. We found that there is a good agreement between our predicted half-lives and those obtained from semi-empirical formulas such as Royer and UDL.