New look at ± decay of heavy nuclei

Geiger-Nuttall plots of the accurate modern data on partial half-lives for ± decay yield very striking linear correlations. The plots for isotopic sequences which cross the neutron magic number N=126 show clearly the presence of different linear relations for N<126 and N>126. We indicate that this observation and all other data on ground-state to ground-state ± decays for even-even nuclei with 76Z 100 may be accounted for very well by a simple model with fixed parameters. An important ingredient in the model is the proposal that preformed ± particles in the parent nuclei move in orbits with large values of a global quantum number. © 1990 The American Physical Society.