Generalized oscillator strength and Coulomb excitation

Coulomb interaction is characterized by two nondimensional fundamental quantities: the Sommerfeld parameter $\ensuremath{\eta}$ and the adiabaticity parameter $\ensuremath{\xi}={\ensuremath{\eta}}_{f}\ensuremath{-}{\ensuremath{\eta}}_{i}.$ In this different approach, we choose these variables to describe the behavior of the generalized oscillator strength (GOS). The expression we obtain is valid for scattering of electrons, positrons, and nuclei by arbitrary targets. We present asymptotic expansions, in the quantal and semiclassical approximation, of the electric dipole GOS.