Abstract
The great majority of the known nuclides with Z>40, including the so-called stable nuclides, are metastable with respect to several modes of spontaneous superasymmetric splitting. A model extended from the fission theory of alpha decay allows one to estimate the lifetimes and the branching ratios relative to the alpha decay for these natural radioactivities. From a huge amount of systematic calculations it is concluded that the process should proceed with maximum intensity in the trans-lead nuclei, where the minimum lifetime is obtained from parent-emitted heavy ion combinations leading to a magic Pb) or almost magic daughter nucleus. More than 140 nuclides with atomic number smaller than 25 are possible candidates to be emitted from heavy nuclei, with half-lives in the range of – s: , , ,12B, , , , , , , , , , , , , , K, , Sc, , , and Cr. The shell structure and the pairing effects are clearly manifested in these new decay modes.
- Received 5 November 1984
DOI:https://doi.org/10.1103/PhysRevC.32.572
©1985 American Physical Society