"ISINN-32" Empirical predictions of α-decay and spontaneous fission half-lives in the decay chains of elements 119 and 120

The competition between α~decay and spontaneous fission in the decay chains of isotopes with $Z = 119$ and $120$ is investigated using empirical formulas. The α-decay half-lives are calculated using the Viola--Seaborg semi-empirical formula, while the spontaneous fission half-lives are evaluated using an empirical formula based on the neutron excess $N-Z$ and the α-decay energy Q_α. The reliability of the approach is validated against experimental data for known nuclei with Z ≥ 103. A number of α-decay chains are identified as promising for experimental observation, with six or more consecutive α~decays expected before termination by spontaneous fission. The present results may be of interest for future experimental searches for superheavy nuclei.