Elastic Scattering of Electrons and Positrons by Lithium Atoms

The eikonal approximation has been used to investigate $e^{\pm }-\mathrm{L}\mathrm{i}$ scattering in the energy region $E=0.8\mathrm{}$ to 500 eV. In addition to the static potential, the effect of the polarization potential has been included explicitly. Our results for the total cross section of $e^{-}-\mathrm{L}\mathrm{i}$ scattering in the energy region $4\le E\le 10$ eV are in close agreement with the recent experimental findings as well as with the theoretical results obtained by various authors using the close-coupling approximation. In the energy region $10<E\le 500$ eV, the present approach yields higher values than first Born approximation (FBA). Our results for the total cross section for $e^{+}-\mathrm{L}\mathrm{i}$ scattering in the eikonal approximation are displayed and compared with the corresponding polarized FBA results and the results obtained by the polarized-orbital method. Results for the differential cross sections for both the systems $e^{\pm }-\mathrm{L}\mathrm{i}$ in the eikonal approximation are also presented together with the corresponding polarized FBA results.