Generation of relativistic positrons carrying intrinsic orbital angular momentum

Abstract

High energy positrons can be efficiently created through high-energy photons splitting into electron-positron pairs under the influence of the Coulomb field. Here we show that a new degree of freedom-the intrinsic orbital angular momentum (OAM) can be introduced into relativistic positrons when the incident photons are twisted. We developed the full-twisted scattering theory to describe the transfer of angular momentum before and after the interaction. It is found that the total angular momentum (TAM) of the photon is equally distributed among the positron and electron. For each photon TAM value, the generated leptons gain higher average OAM number when the photon spin is anti-parallel to its TAM. The impact of photon polarization on the OAM spectrum profile and the scattering probability is more significant at small photon TAM numbers, owing to the various interaction channels influenced by flipping the photon spin. Our work provides the theoretical basis to study OAM physics in particle scattering and to obtain copious relativistic vortex positrons through the Beth-Heitler process.

15 pages, 4 figures

References in corpus (2)

• Semiclassical Dynamics of Electron Wave Packet States with Phase Vortices
• Production of highly-polarized positrons using polarized electrons at MeV energies

Cited by in corpus (6)

• Promises and challenges of high-energy vortex states collisions
• Vortex $\gamma$ photon generation via spin-to-orbital angular momentum transfer in nonlinear Compton scattering
• Generation of Ultrarelativistic Vortex Leptons with Large Orbital Angular Momenta
• Spin-Textured Neutron Beams with Orbital Angular Momentum
• Nonstationary Laguerre-Gaussian states in magnetic field
• Transfer of spin to orbital angular momentum in the Bethe-Heitler process