A multichannel theory for the positron annihilation above the positronium formation threshold based on the modified Faddeev equation is presented. Its relation with the one channel effective charge formula is discussed. Application to the positron-hydrogen scattering has been carried out. A number of positron-electron direct annihilation cross sections in the Ore gap between Ps(1s) and H (n = 2) thresholds are reported. A sharp increase in the calculated annihilation cross section near a Feshbach resonance and followed by an even more drastic decrease of the annihilation cross section across the resonant energy is found for all first S, P and D wave Feshbach resonances.

Original languageEnglish
Pages (from-to)25-30
Number of pages6
JournalNuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms
Volume247
Issue number1 SPEC. ISS.
DOIs
StatePublished - 1 Jan 2006

    Research areas

  • ee annihilation in flight, Modified Faddeev equations

    Scopus subject areas

  • Nuclear and High Energy Physics
  • Instrumentation

ID: 36563801