Polarization potential for dipole excitations.
LJ Allen, I Bray, IE McCarthy
Phys Rev A Gen Phys | Published : 1988
The long-range elastic scattering from a many-electron target is due to virtual dipole excitations. For large enough partial-wave quantum number L it is a weighted sum of contributions from single-orbital dipole excitations for which the second Born approximation is valid. It is shown analytically that the corresponding potential is strictly nonlocal but is phase equivalent for large enough L to the adiabatic potential -α/2r4. A detailed numerical investigation is carried out for intermediate L values both of the T-matrix elements and the phase-equivalent local potential. An excellent simple approximation is found. Numerical examples involve the lowest dipole excitations of hydrogen and sodi..View full abstract