|Low energy phenomena||Photoelectric effect|
|Mid-energy phenomena||Compton scattering|
|High energy phenomena||Pair production|
Pair production refers to the creation of an elementary particle and its antiparticle, usually from a photon (or another neutral boson). Introduction When a Metallic surface is exposed to Electromagnetic radiation above a certain threshold Frequency, the light is absorbed and Electrons The Compton shift formula Klein-Nishina formulaCompton used a combination of three fundamental formulas representing the various aspects of classical and modern physics combining In Particle physics, an elementary particle or fundamental particle is a particle not known to have substructure that is it is not known to be made to most kinds of particles, there is an associated antiparticle with the same Mass and opposite Electric charge. In Physics, the photon is the Elementary particle responsible for electromagnetic phenomena In Particle physics, bosons are particles which obey Bose-Einstein statistics; they are named after Satyendra Nath Bose and Albert Einstein This is allowed, provided there is enough energy available to create the pair – at least the total rest mass energy of the two particles – and that the situation allows both energy and momentum to be conserved (though not necessarily on shell). In Physics and other Sciences energy (from the Greek grc ἐνέργεια - Energeia, "activity operation" from grc ἐνεργός In Physics, mass–energy equivalence is the concept that for particles slower than light any Mass has an associated Energy and vice versa. In Physics, particularly in Quantum field theory, configurations of a physical system that satisfy classical Equations of motion are called on shell All other conserved quantum numbers (angular momentum, electric charge) of the produced particles must sum to zero — thus the created particles shall have opposite values of each (for instance, if one particle has strangeness +1 then another one must have strangeness −1). In Physics, the angular momentum of a particle about an origin is a vector quantity equal to the mass of the particle multiplied by the Cross product of the position Electric charge is a fundamental conserved property of some Subatomic particles which determines their Electromagnetic interaction.
In nuclear physics, this occurs when a high-energy photon interacts with an atomic nucleus, allowing it to produce an electron and a positron without violating conservation of momentum. Nuclear physics is the field of Physics that studies the building blocks and interactions of Atomic nuclei. In Physics, the photon is the Elementary particle responsible for electromagnetic phenomena The nucleus of an Atom is the very dense region consisting of Nucleons ( Protons and Neutrons, at the center of an atom The electron is a fundamental Subatomic particle that was identified and assigned the negative charge in 1897 by J The positrons or antielectron is the Antiparticle or the Antimatter counterpart of the Electron. In Classical mechanics, momentum ( pl momenta SI unit kg · m/s, or equivalently N · s) is the product Since the momentum of the initial photon must be absorbed by something, pair production cannot occur in empty space out of a single photon; the nucleus is needed to conserve both momentum and energy.
Pair production can only occur if the photon has an energy exceeding the twice the rest mass(me) of an electron (1. 022 MeV); the same applies for the generation of other higher energy leptons such as the muon and tau. These interactions were first observed in Patrick Blackett's counter-controlled bubble chamber, leading to the 1948 Nobel Prize in Physics. Patrick Maynard Stuart Blackett Baron Blackett OM CH FRS ( 18 November 1897 &ndash 13 July 1974) was an A bubble chamber is a vessel filled with a superheated transparent Liquid (most often Liquid hydrogen) used to detect electrically charged The Nobel Prize in Physics (Nobelpriset i fysik is awarded once a year by the Royal Swedish Academy of Sciences.
In semiclassical general relativity, pair production is also invoked to explain the Hawking radiation effect. In Physics, the adjective semiclassical has different precise meanings depending on the context General relativity or the general theory of relativity is the geometric theory of Gravitation published by Albert Einstein in 1916 Hawking radiation (also known as Bekenstein-Hawking radiation) is a Thermal radiation with a black body spectrum predicted to be emitted by Black holes According to quantum mechanics, at short scales short-lived particle-pairs are constantly appearing and disappearing (see quantum foam); in a region of strong gravitational tidal forces, the two particles in a pair may sometimes be wrenched apart before they have a chance to mutually annihilate. Quantum mechanics is the study of mechanical systems whose dimensions are close to the Atomic scale such as Molecules Atoms Electrons Quantum foam, also referred to as spacetime foam, is a concept in Quantum mechanics, devised by John Wheeler in 1955. The tidal force is a secondary effect of the Force of Gravity and is responsible for the Tides It arises because the gravitational acceleration experienced Annihilation is defined as "total destruction" or "complete obliteration" of an object having its root in the Latin nihil (nothing When this happens in the region around a black hole, one particle may escape, with its antiparticle being captured by the hole. A black hole is a theoretical region of space in which the Gravitational field is so powerful that nothing not even Electromagnetic radiation (e
Pair production is also the hypothesized mechanism behind the Pair instability supernova type of stellar explosions, where pair production suddenly lowers pressure inside a supergiant star, leading to a partial implosion, and then explosive thermonuclear burning. A pair instability Supernova occurs when Pair production, the production of free Electrons and Positrons in the collision between Atomic Supernova SN 2006gy is hypothesized to have been a pair production type supernova. A supernova (plural supernovae or supernovas) is a stellar Explosion. SN 2006gy was an extremely energetic Supernova, sometimes referred to as a Hypernova or Quark-nova, that was discovered on September 18,