Polarized QED cascades
Abstract
By taking the spin and polarization of the electrons, positrons and photons into account in the strong-field QED processes of nonlinear Compton emission and pair production, we find that the growth rate of QED cascades in ultra-intense laser fields can be substantially reduced. While this means that fewer particles are produced, we also found them to be highly polarized. We further find that the high-energy tail of the particle spectra is polarized opposite to that expected from Sokolov–Ternov theory, which cannot be explained by just taking into account spin-asymmetries in the pair production process, but results significantly from ‘spin-straggling’. We employ a kinetic equation approach for the electron, positron and photon distributions, each of them spin/polarization-resolved, with the QED effects of photon emission and pair production modelled by a spin/polarization dependent Boltzmann-type collision operator. For photon-seeded cascades, depending on the photon polarization, we find an excess or a shortage of particle production in the early stages of cascade development, which provides a path towards a controlled experiment. Throughout this paper we focus on rotating electric field configuration, which represent an idealized model and allows for a straightforward interpretation of the observed effects.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- May 01, 2021
- Source ID
- 10.1088/1367-2630/abf584
Entities
People
- Alexander G. Thomas
- C. P. Ridgers
- D. Seipt
- Dario Del Sorbo
Organizations
- Air Force Office of Scientific Research
- Army Research Office
- Division of Physics
- Engineering and Physical Sciences Research Council