Pair production

Pair production is the creation of a particle and its antiparticle from energy, most commonly when a high-energy photon interacts with a nucleus or another photon.

Electron–positron pair production: The creation of an electron and a positron from energy, usually through a high-energy photon interaction. This is the most familiar form and illustrates the process’s energy threshold.
Antimatter: Matter composed of antiparticles, which have the same masses as corresponding particles but opposite charges and other quantum numbers. Every pair-production event creates a particle together with its antimatter counterpart.
Pair-production spectrometer: A gamma-ray instrument that converts photons into charged pairs and measures their tracks or energies. These instruments infer a gamma ray’s properties from the electron and positron it creates.
Compton scattering: The scattering of a photon by a charged particle, with energy transferred between them. Unlike pair production, it leaves the photon present and does not create a particle–antiparticle pair.
Breit–Wheeler process: The conversion of two photons into an electron–positron pair. It shows how pair production can occur through photon–photon collisions without a nucleus.
Photon: The quantum of the electromagnetic field, with zero rest mass and energy proportional to frequency. Photons provide the energy in the best-known pair-production mechanisms.
Gamma-ray astronomy: The study of astronomical objects through their highest-energy electromagnetic radiation. Space telescopes use pair conversion to detect gamma rays that cannot be focused with ordinary mirrors.
Photoelectric effect: The absorption of a photon by a bound electron, which is ejected from an atom. It converts photon energy into an electron’s kinetic energy rather than creating new massive particles.
Bethe–Heitler process: The production of an electron–positron pair by a photon in the electromagnetic field of a nucleus. It describes the common nuclear-field route and the nucleus’s role in conserving momentum.
Rest energy: The energy associated with an object’s mass at rest, given by Einstein’s relation E = mc². At least the combined rest energy of both particles must be supplied.

Linked from 31 pages