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[en] A model to treat state-dependent short-range correlations in finite nuclei is developed. The model is applied to study the effects of the various correlation channels on the nuclear charge distribution. Results for the ²⁰⁸Pb nucleus are presented

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[en] A computer calculation was developed for bound states using the nonlocal potential (Perey-Buck potential). The parameters of the folding model fitted on Hartree-Fock-Bogolyubov results are given for ²⁰⁸Pb

[en] The Landau-Migdal theory of finite Fermi systems is briefly reviewed with special emphasis on the following: (a) the determination, from an eigenvalue problem, of the energies and particle-hole amplitudes of the excited states of an even-even nucleus with a filled shell for protons and neutrons; (b) the determination of the electromagnetic transition amplitudes of this nucleus and its neighbouring nuclei. The eigenvalue problem is identical to the random phase approximation (RPA) eigenvalue problem with angular momentum coupling, which is derived in detail from the angular momentum uncoupled RPA equations. A calculational formalism has been developed for limited applications of the RPA model and the Landau-Migdal theory of finite Fermi systems. Test calculations were performed for ²⁰⁸Pb and its neighbouring nuclei. The RPA interaction matrix was calculated from the Woods-Saxon single particle wave functions and the Migdal delta-force, which acts as the effective residual nucleon-nucleon interaction

[en] Average elastic photon scattering cross sections were measured for Bi, ²⁰⁸Pb, ²⁰⁷Pb, ²⁰⁶Pb, Tl, Hg, Ce, and Ba at excitations between 4.5 MeV and the respective neutron emission thresholds. The incident photon energy resolution ranged from 50 to 150 keV. Ground-state transition widths were determined from the scattering data for 7 strong individual levels in ²⁰⁸Pb, and total photon absorption cross sections were inferred for Tl, Hg, Ce, and Ba by using reasonable assumptions about level densities and total radiative widths. The cross sections of the nuclei in the Pb region were found to be characterized by two distinct concentrations of transition strength centered at about 5.5 and 7 MeV. The strength near 5.5 MeV in doubly magic ²⁰⁸Pb amounts to 0.5 percent of the dipole sum, and that near 7 MeV, to about 1 percent. In the neighboring isotopes this strength is distributed among many more levels than in ²⁰⁸Pb, but it remains reasonably localized and the total amount of strength seems to stay about constant. Structure observed in the Ce and Ba cross sections was found to be neither as localized nor as pronounced as that in the nuclei near Pb. In addition, the inferred total absorption cross sections of Ba and Ce fall well below what would be expected from a low-energy extrapolation of the giant dipole resonance Lorentzian. For the nuclei of the Pb region, the total transition strength seems to be in excess of the value expected from the Lorentz extrapolation. For ²⁰⁸Pb the excess is about 25 percent in the energy range from 4.8 to 7.4 MeV

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