The presence of vortices in the ionization of hydrogen atoms by positrons at intermediate impact energies is investigated. The present findings show that a previously reported minimum in the fully differential cross section is the signature of a vortex in the continuum positron-electron-proton system. The behaviour of the real and imaginary parts of the complex-valued transition matrix is studied in order to determine and characterize the vortex in momentum space. The obtained information is translated to fully differential ionization cross sections, feasible of being measured with currently available techniques.
Journal of Physics B Atomic Molecular Physics
- Pub Date:
- June 2013
- Physics - Atomic Physics
- 9 pages, 3 figures. Submitted to Journal of Physics B. Results for 200 eV impact energy and a discussion of the validity of the approximation employed have been added in this version