$α$-cluster structure above double-shell closures and $α$-decay of $^{104}$Te

An analysis of the $α$ + core properties of $^{104}$Te along with a global discussion on the $α$-cluster structure above the double-shell closures is presented from the viewpoint of the local potential model. The $α$ + core interaction is described by a nuclear potential of (1 + Gaussian)$\times$(W.S. + W.S.$^3$) shape with two free parameters, which has been successfully tested in nuclei of different mass regions. The model produces $Q_α$ values and $α$-decay half-lives for $^{104}$Te in agreement with the 2018 experimental data of Auranen et al. in the energy range $5.13 \; \mathrm{MeV} < Q_α < 5.3 \; \mathrm{MeV}$ using an $α$ preformation factor $P_α = 1$. The comparison of the calculated reduced $α$-widths for the ground state bands of $^{104}$Te, $^{94}$Mo and $^{212}$Po indicates that $^{104}$Te has an $α$-cluster degree significantly higher than $^{94}$Mo and much higher than $^{212}$Po. These results point to $^{104}$Te as a preferential nucleus for $α$-clustering in the $N,Z = 50$ region and corroborate the statement on the superallowed $α$-decay in $^{104}$Te.