α decay and cluster radioactivity of nuclei of interest to the synthesis of Z=119 , 120 isotopes

Abstract

Super-heavy nuclei of interest for the forthcoming synthesis of the isotopes with $Z=119$, 120 are investigated. One of the very interesting latest experiments was performed at the velocity filter SHIP (GSI Darmstadt) trying to produce $^{299}120$ in a fusion reaction $^{248}\mathrm{Cm}(^{54}\mathrm{Cr},3\mathrm{n})^{299}120$. We report calculations of $\ensuremath{\alpha}$-decay half-lives using four models: AKRA (Akrawy), ASAF (analytical superasymmetric fission), UNIV (universal formula), and semFIS (semi-empirical formula based on fission theory). The released energy, $Q$, is calculated using the theoretical model of atomic masses, WS4. For $^{92,94}\mathrm{Sr}$ cluster radioactivity of $^{300,302}120$ we predict a branching ratio relative to $\ensuremath{\alpha}$ decay of $\ensuremath{-}0.10$ and 0.49, respectively, meaning that it is worth trying to detect such kinds of decay modes in competition with $\ensuremath{\alpha}$ decay.