3 papers
hep-ph2025
Probing the vacuum as a chiral medium
T. Heinzl, B. King, A. Mercuri-Baron
We study the circular birefringence experienced by linearly polarised photons colliding with a circularly polarised background creating a vacuum of definite chirality (handedness).…
hep-ph2024
Coherent enhancement of QED cross-sections in electromagnetic backgrounds
T. Heinzl, B. King, D. Liu
We introduce form factors that relate the amplitude of a QED process in vacuum to its corresponding background-field process. The latter is characterised by a reduced S-matrix elem…
physics.ins-det2024
Letter of Intent: Towards a Vacuum Birefringence Experiment at the Helmholtz International Beamline for Extreme Fields
N. Ahmadiniaz, C. Bähtz, A. Benediktovitch +49
Quantum field theory predicts a nonlinear response of the vacuum to strong electromagnetic fields of macroscopic extent. This fundamental tenet has remained experimentally challeng…