Effective Polarization Charge in the Theory of Finite Fermi Systems

A microscopic method for calculating phenomenological effective polarization charges: (i) of nucleons $$e_{{{\text{eff}}}}^{{SM}}$$ and (ii) of virtual static isoscalar and isovector EL transitions $$e_{{{\text{is}}}}^{{SM}}$$ and $$e_{{{\text{iv}}}}^{{SM}}$$ obtained by fitting to the experiment in modern calculations within the many-particle shell model with a limited model space is considered. The method is based on the theory of finite Fermi systems developed by Migdal. The used approximation of separable forces has strongly simplified calculations. The $${{e}^{{SM}}}$$ values for 208Pb and 120Sn have been calculated for the first time and compared with phenomenological values. Our results demonstrate the necessity and possibilities for further microscopic analysis of the obtained $${{e}^{{SM}}}$$ values in the process of generalization and development of the theory of finite Fermi systems.