@article {rost1994ionization,
	title = {Ionization of hydrogen by positron impact near the fragmentation threshold},
	journal = {Physical Review A},
	volume = {49},
	year = {1994},
	pages = {R4289},
	publisher = {APS},
	abstract = {The semiclassical approximation of Feynman{\textquoteright}s path integral is used to calculate the S matrix for the positron-impact ionization of hydrogen. The formulation provides a full scattering amplitude, and more importantly does not require knowledge of the asymptotic three-body Coulomb state in the continuum. In the limit of vanishing excess energy, the results confirm Wannier{\textquoteright}s classical model for fragmentation [Phys. Rev. 90, 817 (1953)]. The experimentally observable ratio of fragmentation versus total ionization (including positronium formation) is predicted.},
	url = {https://doi.org/10.1103/PhysRevA.49.R4289},
	author = {Rost, Jan M and Heller, EricJ.}
}
