Method of Green’s Function for Polarizabilities and Mean Excitation Energies of Ground- and Excited-State Hydrogen-Like Atoms

Abstract

Using the Coulomb Green function, general expressions are derived for the static and dynamic dipole polarizabilities of hydrogen-like atoms in arbitrary states. Also calculated for the hydrogen atom in the 1s and 2s states are the exact mean excitation energies relevant to the Lamb shift, the stopping power and its mean fluctuation, and the total cross section for fast charged particles colliding with the atoms.