Favoured alpha decays of odd-mass nuclei

Abstract

The authors examine the alpha decays of heavy odd-mass nuclei, selecting those transitions which appear to proceed with the least hindrance due to nuclear structure incompatibilities between parent and daughter. They analyse the half-lives of 255 of these favoured transitions using a simple cluster model, and reproduce the absolute values of 216 of them to within a factor of 3. They achieve this level of agreement using exactly the same set of cluster model parameter values previously employed in an analysis of alpha decay of heavy even-even nuclei. In that analysis 125 out of a total of 154 half-lives were reproduced to within a factor of approximately 2. They conclude that this excellent overall fit provides strong evidence for the existence of preformed alpha particles in heavy nuclei, moving in orbits with large values of a global quantum number.