Further exploration of the machine-learning-based nuclear mass table

Abstract

The mass of the atomic nucleus, as one of the fundamental physical quantities of the atomic nucleus, plays an important role in understanding and researching the structure of the atomic nucleus and nuclear reactions, and the basic interactions between nucleons. However, accurately predicting the mass of nuclei far from the β stability line remains a huge challenge. Based on the machine-learning-refined mass model, we investigate the newly measured atomic nucleus masses since 2022, along with the residual proton-neutron interaction (δVpn) and the α-decay energy of heavy nucleus. It is found that: 1) For the 23 newly measured atomic nuclei, the root mean square deviations obtained by the machine-learning-refined mass models are between 0.51 and 0.58 MeV, which are significantly lower than 3.275, 1.058, 0.752, and 0.785 MeV given by the liquid droplet model (LDM), Weizsäcker-Skyrme-4 (WS4), finite-range droplet model (FRDM), and Duflo-Zucker (DZ), respectively. 2) The δVpn of the atomic nucleus with N = Z obtained from machine-learning-refined mass models is consistent with the latest experimental data. 3) The root mean square deviations of the α-decay energy of heavy nuclei obtained from the machine-learning-refined mass models have also been significantly reduced. Furthermore, by employing the Bayesian model average approach to combine the results from different machine-learning-refined mass models, we obtain more accurate predictions. These findings demonstrate that such models have good extrapolation capabilities and provide useful insight for further research. The datasets presented in this paper are openly available at https://doi.org/10.57760/sciencedb.j00213.00246.