α-decay half-lives of superheavy nuclei within a one-parameter model

Abstract：

The α-decay half-lives of superheavy nuclei (SHN) with charge numbers $ Z \geq 104 $ are investigated by employing a phenomenological one-parameter model based on quantum-mechanical tunneling through a potential barrier, where both the centrifugal and overlapping effects have been considered. It is shown that the experimental α-decay half-lives of the 81 SHN are reproduced well. Moreover, the order of magnitude for the α-particle preformation probability inside a parent nucleus ( $S_{ {\alpha }} $ ) is found to be $ 10^{-2} $ . Then, within this model, the $S_{ {\alpha }} $ values and α-decay half-lives of Z= 118−120 isotopes are predicted by inputting the α-decay energies ( $ Q_{\alpha } $ ) extracted from the relativistic continuum Hartree-Bogoliubov (RCHB) theory, Duflo-Zuker 19 (DZ19, where 19 denotes the number of fitting parameters) model, improved Weizsacker-Skyrme (lMWS) model, and machine learning (ML) approach. By analyzing the evolutions of $ Q_{\alpha } $ , $S_{ {\alpha} }$ and α-decay half-lives of Z= 118−120 isotopes with the neutron number Nof the parent nucleus, it is found that the shell effect at N= 184 is evident for all nuclear mass models. Meanwhile, for the case of the RCHB, N= 172 is determined as a submagic number. However, the submagic number at N= 172 is replaced by N= 178 for the ML approach.