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Abstract

Quantum electrodynamics in an intense plane-wave field is considered within the framework
of light-cone quantization. In this context, high-energy vacuum birefringence and
dichroism in an intense laser field are investigated. In particular, a setup is analyzed,
in which probe gamma photons are generated via Compton backscattering, propagate
through an intense laser pulse, and are subsequently detected via pair production in matter.
The polarization of the photon beam is characterized by the Stokes parameters, and
their change due to vacuum birefringence and dichroism is determined. The magnitude
of the polarization effects is assessed for upcoming high-power laser facilities. Optimal
parameters and regimes are identified, and the required statistics and the duration of the
experiment in order to confirm the prediction of quantum electrodynamics are estimated.
Furthermore, an approach for the treatment of the bispinor part of scattering amplitudes
in a plane-wave field is introduced. Simplified expressions for the vertex functions, arising
from the interaction terms of the lightfront Hamiltonian, are obtained. It is demonstrated
that with the developed technique the evaluation of the gamma-matrix traces for scattering
in an external plane-wave field can be performed in a relatively straightforward way
and the final results can be written in a compact form.