Comparison of elastic scattering of electron, positron and positronium from helium*

There exists a remarkable degree of similarity between the total cross section for electron and positronium scattering as a function of velocity from a number of targets, including helium \cite{[1]}. We have computed $s$-, $p$-, $d$- and $f$-wave phase shifts for elastic positron-helium scattering using the Kohn and inverse Kohn variational methods \cite{[2],[3]}. Using phase shifts for positron, electron and positronium scattering from helium, we have computed partial-wave, elastic differential, elastic integrated and momentum-transfer cross sections \cite{[4]}. We plan to show a comparison of various cross sections as a function of velocity for the three projectiles.

\begin{thebibliography}{References}

\bibitem{[1]} S.~J.~Brawley, S.~Armitage, J.~Beale, D.~E.~Leslie, A.~I.~Williams, G.~Laricchia, Science {\bf 330}, 789 (2010).

\bibitem{[2]} P.~Van Reeth and J.~W.~Humberston, J.~Phys.~B {\bf 32}, 3651 (1999).

\bibitem{[3]} C.~M.~DeMars, S.~J.~Ward and P.~Van Reeth, {\it unpublished}.

\bibitem{[4]} Josiah Claypool, {\it Senior Thesis UNT}, 2020, {\it unpublished}.

\end{thebibliography}

The North Texas Scientific Computing (NTSC), a division under the office of the CIO at University of North Texas, is acknowledged for providing Talon computational resources.