α-cluster structure above double closed shells

Abstract

Spectra, reduced electromagnetic $B(E2)$ transition strengths, mean-square charge radii and, for those states above the emission threshold, \ensuremath{\alpha}-decay widths are calculated by using a local potential cluster model for the ground state ${K}^{\ensuremath{\pi}}={0}^{+}$ and first-excited ${K}^{\ensuremath{\pi}}={0}^{\ensuremath{-}}$ bands of $^{20}\mathrm{Ne}, ^{44}\mathrm{Ti}, ^{94}\mathrm{Mo}, ^{104}\mathrm{Te}$, and $^{136}\mathrm{Te}$. These nuclei are all modeled as $\ensuremath{\alpha}$-particles outside double-closed-shell core. The nuclear cluster-core potential is taken as a mixture of Saxon-Woods and cubed Saxon-Woods terms whose depths, radii, and diffuseness parameters are determined by the double folding Michigan-3-Yukawa potential model. Generally good agreement with experimental data is obtained without the introduction of effective charges, and predictions are made for many as yet unmeasured quantities in the two Te isotopes.