Landau Migdal Theory of Interacting Fermi Systems: A Framework for Effective Theories in Nuclear Structure Physics

Abstract

We review Migdal's Theory of Finite Fermi Systems and its application to the structure of nuclei. The theory is an extension of Landau's Theory of Interacting Fermi Systems. In the first part the basic formulas are derived within the many body Green functions approach. The theory is applied to isovector electric giant resonances in medium and heavy mass nuclei. The parameterizations of the enormalized effective ph-interaction and the effective operators are discussed. It is shown that the number of free parameters are restricted due to conservation laws. We also present an extension of Migdal's theory, where the low-lying phonons are considered in a consistent manner. The extended theory is again applied to the same isovector electric giant resonances and to the analysis of $(α,α^\prime)$ reaction data. We point out that the extended theory is the appropriate frame for self consistent nuclear structure calculations starting from effective Lagrangians and Hamiltonians.