Anharmonic perturbation of neutron-proton pairs by the unpaired neutrons in heavy finite nuclei

Abstract

The properties of a finite heavy nucleus in which the number of neutrons N is not equal to the number of protons Z, N > Z, have been studied. It is assumed that the core of the nucleus is composed of proton-neutron pairs and the excess neutrons constitute the surface region of the nucleus. The interaction between a neutron and a proton constituting the neutron-proton pair is assumed to be harmonic. The unpaired neutrons in the surface region are assumed to interact with the neutron–proton pairs in the core of the nucleus anharmonically. Many body perturbation theory has been used to calculate the total energy of the nucleus, and thereby, we have calculated the binding energy per nucleon, called the binding fraction, the specific heat and the transition temperature. Speculation, as to how the alpha, beta and gamma radiations are emitted by a heavy nucleus, is also presented.