Abstract
Coulomb displacement energies in a series of isotopes generally decrease with . This decrease can arise from an increase with of the average distance of interaction between pairs of protons. In the shell model a decrease can also result from charge-independence-breaking effects if the neutron-proton interaction for the valence nucleons is more attractive than the neutron-neutron interaction. Using the model recently proposed by Sherr and Talmi for the shell, existing data for this shell and also the and shells were analyzed allowing all matrix elements to vary as . Least squares calculations of the rms deviation were carried out for varying values of from -2 to +2. It was found that although there was a minimum in vs it was too shallow to exclude any for -1 to +1 in the and shells or 0 to +1 in the shell. It is therefore not possible to distinguish between dependence and charge dependence in this model. The magnitude of the latter as expressed in terms of matrix elements depends strongly on the former. As increases from -1 to +1, these matrix elements decrease roughly linearly in absolute magnitude and eventually change sign. For they have appreciable and reasonable magnitudes for the and shells but for the shell the values are too small to be considered significant.
NUCLEAR STRUCTURE Shell model analysis of Coulomb displacement energies in ground state multiplets in , , and shells.
- Received 18 March 1977
DOI:https://doi.org/10.1103/PhysRevC.16.1159
©1977 American Physical Society