Ronen's golden rule for cluster radioactivity

In nuclear physics, Ronen's golden rule for cluster radioactivity is that the most favorable parents for heavy ion emission (cluster radioactivity) are those that emit clusters which have atomic mass $$A_{z}$$ which is given by $$A_{z}=A_{z-2}+4+B_{z/2}$$. The atomic number $$Z$$ is even, $$A_{0}=0$$, $$B_{z/2}=0$$ for $$Z/2$$ - odd and $$B_{z/2}=2$$ for $$Z/2$$ - even. The daughter nuclei is preferably magic, close to the double magic 208Pb.