Microscopic description of superallowedα-decay transitions

Abstract

It was recently found that the formation probabilities of $\ensuremath{\alpha}$ particles in Te isotopes are larger than the corresponding probabilities in Po isotopes. We have done a full microscopic calculation within the framework of the multistep shell model to analyze in detail the formation probabilities and subsequent decays of $\ensuremath{\alpha}$ particles from $^{212}\mathrm{Po}$ and $^{104}\mathrm{Te}$. We have also calculated the spectra of these two decaying nuclei and found that the tentatively assigned spin $({18}^{+})$ at 2.922 MeV in $^{212}\mathrm{Po}$ (National Nuclear Data Center, www.nndc.bnl.gov) is predicted to be a state ${16}^{+}$. We also present for the first time the full energy spectrum of $^{104}\mathrm{Te}$. The evaluated formation amplitudes in both nuclei show that in $^{104}\mathrm{Te}$ there is indeed a superallowed $\ensuremath{\alpha}$-decay transition.