Quantum electrodynamics

A photon () is an elementary particle that is a quantum of the electromagnetic field, including electromagnetic radiation such as light and radio waves, and the force carrier for the electromagnetic force. Photons are massless particles that can only move at one speed, the speed of light measured in a vacuum. The photon belongs to the class of boson particles.

The positron or antielectron is the particle with an electric charge of +1e, a spin of 1/2 ħ (the same as the electron), and the same mass as an electron. It is the antiparticle (antimatter counterpart) of the electron. When a positron collides with an electron, annihilation occurs. If this collision occurs at low energies, it results in the production of two or more photons.

Abelian gauge theory describing quantum interactions of the electromagnetic field with matter

scattering of a photon off of a charged particle

lowest possible energy of a quantum system or field

thumb|200px|right|An electron and [[positron orbiting around their common centre of mass. An s state has zero angular momentum, so orbiting around each other would mean going straight at each other until the pair of particles is either scattered or annihilated, whichever occurs first. This is a bound quantum state known as positronium.]]

thumb|upright|Bremsstrahlung produced by a high-energy electron deflected in the electric field of an atomic nucleus

difference in energy of hydrogenic atom electron states not predicted by the Dirac equation

alt=Simplified drawing of the muonium atom|thumb|300x300px|A muonium atom

virtual anti-particle pair production giving self-energy to the electromagnetic field

quantum field-theoretic differences of magnetic properties than expected from classical theories

electron-photon scattering cross section

Predicted physical phenomenon in QED

In quantum field theory, the energy that a particle has as a result of changes that it causes in its environment defines its self-energy \Sigma. The self-energy represents the contribution to the particle's energy, or effective mass, due to interactions between the particle and its environment. In electrostatics, the energy required to assemble the charge distribution takes the form of self-energy by bringing in the constituent charges from infinity, where the electric force goes to zero. In a condensed matter context, self-energy is used to describe interaction induced renormalization of quas

Physics postulate describing all electrons/positrons as one time-independent entity

Di-positronium, or dipositronium, is an exotic molecule consisting of two atoms of positronium. It was predicted to exist in 1946 by John Archibald Wheeler, and subsequently studied theoretically, but was not observed until 2007 in an experiment performed by David Cassidy and Allen Mills at the University of California, Riverside. The researchers made the positronium molecules by firing intense bursts of positrons into a thin film of porous silicon dioxide. Upon slowing down in the silica, the positrons captured ordinary electrons to form positronium atoms. Within the silica, these were long l

chemical compound

identity in abelian gauge theories due to gauge invariance

branch of particle physics concerning interactions between two photons

procedure of coping with redundant degrees of freedom in physical field theories

physical process for creating a positron-electron pair from the collision of two photons

deflection of high-energy photons in the Coulomb field of nuclei as a consequence of vacuum polarization

hypothesised phenomenon in quantum field theory

coulomb potential with vacuum polarization corrections

describing the interaction between a photon and an electron

effective quantum electrodynamics action for the non-linear dynamics of electromagnetic fields in vacuum

nonlinear generalization of electrodynamics with a maximum field strength

electron-positron scattering

lowest-energy state

theorem in quantum physics that, in a theory preserving charge conjugation symmetry, a Feynman diagram consisting of a closed fermion loop connected to an odd number of vertices integrates to zero

electron-electron scattering in quantum field theory

quantum electrodynamics in 1+1 dimensions

critical field in QED

energy scale (10²⁸⁶ eV) at which the interaction strength of quantum electrodynamics becomes infinite when computed perturbatively