Strong-field QED in Furry-picture momentum-space formulation: Ward identities and Feynman diagrams
arXiv:2303.12941 · doi:10.1103/PhysRevD.108.016013
Abstract
The impact of a strong electromagnetic background field on otherwise perturbative QED processes is studied in the momentum-space formulation. The univariate background field is assumed to have finite support in time, thus being suitable to provide a model for a strong laser pulse in plane-wave approximation. The usually employed Furry picture in position space must be equipped with some non-obvious terms to ensure the Ward identity. In contrast, the momentum space formulation allows for an easy and systematic account of these terms, both globally and order-by-order in the weak-field expansion. In the limit of an infinitely long-acting (monochromatic) background field, these terms become gradually suppressed, and the standard perturbative QED Feynman diagrams are recovered in the leading-order weak-field limit. A few examples of three- and four-point amplitudes are considered to demonstrate the application of our Feynman rules which employ free Dirac spinors, the free photon propagator, and the free Fermion propagator, while the external field impact is solely encoded in the Fermion-Fermion-photon vertex function. The appearance of on-/off-shell contributions, singular structures, and Oleinik resonances is pointed out.
References in corpus (40)
- Extremely high-intensity laser interactions with fundamental quantum systems
- Advances in QED with intense background fields
- Charged particle motion and radiation in strong electromagnetic fields
- On the Observation of Vacuum Birefringence
- Trident pair production in strong laser pulses
- Enhanced subthreshold electron-positron production in short laser pulses
- Nonlinear double Compton scattering in the full quantum regime
- Two-photon Compton process in pulsed intense laser fields
- Note on the conjectured breakdown of QED perturbation theory in strong fields
- Conjecture of perturbative QED breakdown at
- Nonperturbative treatment of double Compton backscattering in intense laser fields
- Depletion of intense fields
- Analytical results for non-linear Compton scattering in short intense laser pulses
- Exact WKB analysis of the vacuum pair production by time-dependent electric fields
- Single and double nonlinear Compton scattering
- Polarization operator for plane-wave background fields
- Breit-Wheeler process in very short electromagnetic pulses
- Correlated two-photon emission by transitions of Dirac-Volkov states in intense laser fields: QED predictions
- Approximating higher-order nonlinear QED processes with first-order building blocks
- Back-reaction on background fields: a coherent state approach
- Non-linear Breit-Wheeler process in short laser double-pulses
- Optimizing Laser Pulses for Narrowband Inverse Compton Sources in the High-Intensity Regime
- Caustic structures in the spectrum of x-ray Compton scattering off electrons driven by a short intense laser pulse
- Non-linear Breit-Wheeler process with linearly polarized beams
- Spectral caustics in laser assisted Breit-Wheeler process
- Electron distributions in nonlinear Compton scattering
- Resummation of background-collinear corrections in strong field QED
- Laser assisted Compton scattering of X-ray photons
- On the Heisenberg limit for detecting vacuum birefringence
- Pair production by Schwinger and Breit-Wheeler processes in bi-frequent fields
- Laser pulse-length effects in trident pair production
- Multi-photon regime of non-linear Breit-Wheeler and Compton processes in short linearly and circularly polarized laser pulses
- Using nonlinear Breit-Wheeler to test nonlinear vacuum birefringence
- The analytic structure of amplitudes on backgrounds from gauge invariance and the infra-red
- Theoretical study of the Compton effect with correlated three-photon emission: From the differential cross section to high-energy triple-photon entanglement
- Triple Compton effect: A photon splitting into three upon collision with a free electron
- QED as a many-body theory of worldlines: I. General formalism and infrared structure
- Non-perturbative signatures of non-linear Compton scattering
- Towards high photon density for Compton Scattering by spectral chirp
- The generation of narrow ultrarelativistic beams of positrons (electrons) in the process of resonant photogeneration of pairs on nuclei in a strong electromagnetic field