Forbidden Beta Decay

Abstract

As the atomic nuclei is a system of nucleons, proton and neutrons, bound together by a strong nuclear force, a study has been made on its structure and physical behaviors. Out of about 1000 nuclides known to exist, only about 25% are stable. The rest are radioactive and are mainly produced artificially. Nuclei with relatively few protons and neutrons, favors the formation of stable nuclei with an approximately equal number of protons and neutrons. For the heavier nuclei, the number of neutrons is higher than the number of protons so that the N/Z ratio becomes greater than 1(stability line) for higher Z. That’s why the stability line is steeper at higher Z. In the lighter nuclei the proton proton and neutron-neutron forces are approximately equal within the nuclei, however in the heavier nuclei; the Coulomb repulsion between the protons tends to weaken the binding. To reduce this, the numbers of neutrons should be relatively higher which increases the strength of binding. This unbalanced situation between neutrons and protons leads to the processes like beta decays, alpha decays etc. Unstable nuclei decay to nuclei closer to the stability until a stable nucleus is reached.