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Pair production often refers specifically to a photon creating an electron–positron pair near a nucleus. As energy must be conserved, for pair production to occur, the incoming energy of the photon must be above a threshold of at least the total rest mass energy of the two particles created. (As the electron is the lightest, hence, lowest ...
Pair production takes place exponentially slowly when the electric field strength is much below the Schwinger limit, corresponding to approximately 10 18 V/m. With current and planned laser facilities, this is an unfeasibly strong electric-field strength, so various mechanisms have been proposed to speed up the process and thereby reduce the ...
Pair production and annihilation: In the Stückelberg–Feynman interpretation, pair annihilation is the same process as pair production: Møller scattering: electron-electron scattering Bhabha scattering: electron-positron scattering Penguin diagram: a quark changes flavor via a W or Z loop Tadpole diagram: One loop diagram with one external leg
A pair-instability supernova is a type of supernova predicted to occur when pair production, the production of free electrons and positrons in the collision between atomic nuclei and energetic gamma rays, temporarily reduces the internal radiation pressure supporting a supermassive star's core against gravitational collapse. [1]
This expression can be derived by using a quantum mechanical symmetry between pair production and Bremsstrahlung. Z {\displaystyle Z} is the atomic number , α f i n e ≈ 1 / 137 {\displaystyle \alpha _{fine}\approx 1/137} the fine structure constant , ℏ {\displaystyle \hbar } the reduced Planck constant and c {\displaystyle c} the speed of ...
The creation of a much more massive pair, like a proton and antiproton, requires photons with energy of more than 1.88 GeV (hard gamma ray photons). The first published calculations of the rate of e + –e − pair production in photon-photon collisions were done by Lev Landau in 1934. [2]
The heaviest particle pairs yet produced by electron–positron annihilation in particle accelerators are W + – W − pairs (mass 80.385 GeV/c 2 × 2). The heaviest single-charged particle is the Z boson (mass 91.188 GeV/c 2).
In explosions of very large stars (250 or more solar masses), photodisintegration is a major factor in the supernova event. As the star reaches the end of its life, it reaches temperatures and pressures where photodisintegration's energy-absorbing effects temporarily reduce pressure and temperature within the star's core.