Intrinsic Nonlocality of Spin- and Polarization-Resolved Probabilities in Strong-Field Quantum Electrodynamics

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autores principales: Montefiori, Samuele, Di Piazza, Antonino, Podszus, Tobias, Keitel, Christoph H., Tamburini, Matteo
Formato: Preprint
Publicado: 2026
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866914386656886784
author Montefiori, Samuele
Di Piazza, Antonino
Podszus, Tobias
Keitel, Christoph H.
Tamburini, Matteo
author_facet Montefiori, Samuele
Di Piazza, Antonino
Podszus, Tobias
Keitel, Christoph H.
Tamburini, Matteo
contents Spin and polarization are central to precision tests of fundamental physics and for interpreting radiation from astrophysical sources and ultraintense laser-matter experiments. Predictive modeling therefore requires not only energy spectra, but also angle-, spin-, and polarization-resolved particle distributions. Here, we demonstrate that a key assumption underlying current strong-field quantum electrodynamics (QED) models, i.e., that emission can be treated as an instantaneous random event sampled from a local differential rate, breaks down once emission angles, electron spin, and/or photon polarization are resolved. Namely, the resulting fully differential distribution can deviate strongly from the true result and can even yield inconsistent probabilities that take negative values. The physical reason is simple: a photon emission probability builds up over a finite length of the electron trajectory, the formation region, during which the electron direction changes by roughly the same small angle that defines the radiation cone. We therefore integrate over this formation region analytically to obtain a physically consistent electron spin and photon polarization model whose implementation is compatible with existing Monte Carlo and particle-in-cell (PIC) workflows. Simulations of a GeV-class electron-laser collision and of emission in a pulsar-like magnetic field reveal spin and polarization patterns that differ even qualitatively from state-of-the-art local models. In particular, our new model predicts substantial angle-dependent circular photon polarization where the standard approach yields none, and a pronounced helicity bias in the recoiling electrons absent from current predictions. These findings have direct implications for upcoming strong-field QED experiments and for interpreting polarized radiation from extreme astrophysical environments.
format Preprint
id arxiv_https___arxiv_org_abs_2603_11148
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Intrinsic Nonlocality of Spin- and Polarization-Resolved Probabilities in Strong-Field Quantum Electrodynamics
Montefiori, Samuele
Di Piazza, Antonino
Podszus, Tobias
Keitel, Christoph H.
Tamburini, Matteo
High Energy Physics - Phenomenology
High Energy Astrophysical Phenomena
Plasma Physics
Spin and polarization are central to precision tests of fundamental physics and for interpreting radiation from astrophysical sources and ultraintense laser-matter experiments. Predictive modeling therefore requires not only energy spectra, but also angle-, spin-, and polarization-resolved particle distributions. Here, we demonstrate that a key assumption underlying current strong-field quantum electrodynamics (QED) models, i.e., that emission can be treated as an instantaneous random event sampled from a local differential rate, breaks down once emission angles, electron spin, and/or photon polarization are resolved. Namely, the resulting fully differential distribution can deviate strongly from the true result and can even yield inconsistent probabilities that take negative values. The physical reason is simple: a photon emission probability builds up over a finite length of the electron trajectory, the formation region, during which the electron direction changes by roughly the same small angle that defines the radiation cone. We therefore integrate over this formation region analytically to obtain a physically consistent electron spin and photon polarization model whose implementation is compatible with existing Monte Carlo and particle-in-cell (PIC) workflows. Simulations of a GeV-class electron-laser collision and of emission in a pulsar-like magnetic field reveal spin and polarization patterns that differ even qualitatively from state-of-the-art local models. In particular, our new model predicts substantial angle-dependent circular photon polarization where the standard approach yields none, and a pronounced helicity bias in the recoiling electrons absent from current predictions. These findings have direct implications for upcoming strong-field QED experiments and for interpreting polarized radiation from extreme astrophysical environments.
title Intrinsic Nonlocality of Spin- and Polarization-Resolved Probabilities in Strong-Field Quantum Electrodynamics
topic High Energy Physics - Phenomenology
High Energy Astrophysical Phenomena
Plasma Physics
url https://arxiv.org/abs/2603.11148