Breit–Wheeler process

This is also the case for the multi-photon Breit–Wheeler, which was observed at the Stanford Linear Accelerator Center in 1997 by colliding high-energy electrons with a counter-propagating terawatt laser pulse.[6][7] Although this mechanism is still one of the most difficult to be observed experimentally on Earth, it is of considerable importance for the absorption of high-energy photons travelling cosmic distances.In 1928, Paul Dirac's work proposed that electrons could have positive and negative energy states following the framework of relativistic quantum theory but did not explicitly predict the existence of a new particle.Although the process is one of the manifestations of the mass–energy equivalence, as of 2017, the pure Breit–Wheeler has never been observed in practice because of the difficulty in preparing colliding gamma ray beams and the very weak probability of this mechanism.They would then fire these electrons into a slab of gold to create a beam of photons a billion times more energetic than those of visible light.To first create the photons and then have the pair production in an all-in-one setup, the similar configuration can be used by colliding GeV electrons.In July 2021 evidence consistent with the process was reported by the STAR detector one of the four experiments at the Relativistic Heavy Ion Collider although it was unclear if it was due to massless photons or massive virtual photons, vacuum birefringence was also studied obtaining evidence enough to claim the first known observation of the process.
The Breit–Wheeler process is the creation of an electron–positron pair following the collision of two high-energy photons (gamma photons).
The nonlinear Breit–Wheeler process or multiphoton Breit–Wheeler is the creation of an electron-positron pair from the decay of a high-energy photon ( gamma photon ) interacting with a strong electromagnetic field such as a laser .
gamma photonpositronelectronphotonsgamma photonselectromagnetic fieldelectron–positron annihilationphoton energyelectron and positron rest mass energygamma-ray laserpair annihilationStanford Linear Accelerator Centerquantum electrodynamicsGregory BreitJohn A. WheelerPhysical ReviewPaul Diracmass–energy equivalencegamma rayImperial College LondonhohlraumMonte Carlo simulationsnon-linear inverse Compton scatteringlinear polarizedelectric fieldwavelengthtitanium-sapphire laserlaser wakefield acceleration regimeSTAR detectorRelativistic Heavy Ion Collidermasslessvirtualvacuum birefringenceTwo-photon physicsBibcodeCiteSeerXNature PhotonicsArs TechnicaEuler–Heisenberg LagrangianFeynman diagramGupta–Bleuler formalismPath integral formulationDual photonFaddeev–Popov ghostPhotonPositroniumVirtual particlesAnomalous magnetic dipole momentFurry's theoremKlein–Nishina formulaLandau poleQED vacuumSelf-energySchwinger limitUehling potentialVacuum polarizationVertex functionWard–Takahashi identityBhabha scatteringBremsstrahlungCompton scatteringDelbrück scatteringLamb shiftMøller scatteringSchwinger effectPhoton-photon scattering