Electronic excitation of atoms by electron and positron impact

Various tests of the Standard Model have yet to explain the matter/antimatter asymmetry in the universe. The energetic photons produced in positron-electron annihilation are not easily

formed into images leading to poor angular resolution in astrophysical observations. This limits our ability to localize and identify sources of positrons from a list of potential

astrophysical processes. Thus, much of our understanding is predicated upon positron transport models. It has recently been shown that excitation processes play an important role

in the number of positrons which survive transport through interstellar media, or the positron survival fraction. We investigate the magnitude of the excitation cross section for both

positrons and electrons and the resulting fluorescence as the atom relaxes to the ground state. Comparisons between available theory and experiment for positron and electron excitation functions will be presented. We will comment on both experimental and theoretical prospects of providing positron and electron excitation functions useful to the astrophysical community.