CHARGE DISTRIBUTION OF EXCITED STATES OF ODD-MASS NUCLEI

From a very general formulation of the theory of interacting Fermi systems with pair correlations, the special case of the Migdal-Larkin theory for finite systems is derived, and the approximations of this theory are discussed. In a rigorous way not based on perturbation theory, the change of the density matrix due to the addition of another particle is derived for a Fermi system with pair correlations. The inhomogeneous term of this equation is identical with the result of the BCS theory in contrast to Migdal's equation. For some odd-mass nuclei in the rare-earth region, the change of the r.m.s. charge radius connected with the transition from the ground state to an excited state is calculated with this equation. The theoretical results are in good agreement with experiment. © 1969.