Transfer of Helicity in Radiation and Absorption of High-Energy Photons

Publisher Website
Google Scholar
Abstract
Nearly complete transfer of momentum between a high-energy electron (or positron) and a photon in a Coulomb field implies that helicity is also transferred. This is not a consequence of conservation of total angular momentum but, rather, of spin angular momentum, and follows from a demonstration that it is possible to use free-particle spinors (though not free wave functions) for the high-energy particles. Polarization correlations of the lower energy particle in such a process are discussed. Applications are made to bremsstrahlung, pair production, photoeffect, and one-photon pair annihilation.