Elastic scattering of electrons and positrons by Pb atoms

The elastic scattering of e$^{\mathrm{\pm }}$ - Pb atoms is reported for 10 eV $\le $E $\le $ 1 keV\textbf{. }A complex optical potential embodying the static, exchange, polarization and absorption potentials is used to solve Dirac equations [1] by partial wave analysis. For electron case the absorption strength (W$_{\mathrm{abs}})$ plays an important role; it increases monotonically from E\textgreater 30 eV but its low energy peak may be due to dispersion effect at the inelastic threshold. As compared to other theoretical values [2] our results show good agreement with available experimental cross sections [3]. [1] P.A.M. Dirac, \textit{Principles of Quantum Mechanics}. International Series of Monographs on Physics (4th ed.), Oxford University Press. p.~255. (1958).. [2] P. Kumar, A. K. Jain, A. N. Tripathi, and S. N. Nahar, Phys. Rev. A 49, 899 (1994). [3] S. Tosic, M. S. Rabasovic, D. Sevic, V. Pejcev, D. M. Filipovic, L. Sharma, A. N. Tripathi, R. Srivastava, and B. P. Marinkovic, Phys. Rev. A77, 012725 (2008).