Abstract
The singularity structure of the forward positron-atom scattering amplitude is studied within the framework of perturbation theory with the use of the Landau rules. The unphysical and anomalous regions in the positron-atom forward dispersion relations are discussed. It is shown that the unphysical region starts at E/sub 0/ = -Vertical BarE(Ps)Vertical Bar+Vertical BarE/sub 1/Vertical Bar and the anomalous region at E/sub a/ = -(..sqrt..2Vertical BarE(Ps)Vertical Bar - ..sqrt..Vertical BarE/sub 1/Vertical Bar )/sup 2/, where E(Ps) and E/sub 1/ are correspondingly the positronium and the atomic-electron binding energies. The anomalous region is on the physical sheet if Vertical BarE(Ps)Vertical Bar/2>Vertical BarE/sub 1/Vertical Bar.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
