title: Laser-assisted positron-impact ionization of atomic hydrogen.
abstract: We study the ionization of atomic hydrogen by a fast positron in the presence of an external linearly polarized laser field. We concentrate on the limit of a small momentum transfer and describe the fast positron's continuum states by Volkov wave functions. The ejected electron is described by a Coulomb-Volkov wave function. We are limited to small laser intensities such that the dressed state of the target is treatable within the time-dependent perturbation theory, even though the laser intensity is still quite high by laboratory standards. Numerical results for the triply differential cross sections and their dependencies on laser-field parameters are discussed and compared with the results of laser-assisted ionization by electron impact.
authors.affiliation: Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui.
authors.forename: Juan
authors.initials: J
authors.lastname: Pan
authors.forename: Shu-Min
authors.initials: SM
authors.lastname: Li
authors.forename: Jamal
authors.initials: J
authors.lastname: Berakdar