Artificial Production
Antiparticles are also produced in any environment with a sufficiently high temperature (mean particle energy greater than the pair production threshold). During the period of baryogenesis, when the universe was extremely hot and dense, matter and antimatter were continually produced and annihilated. The presence of remaining matter, and absence of detectable remaining antimatter, also called baryon asymmetry, is attributed to violation of the CP-symmetry relating matter to antimatter. The exact mechanism of this violation during baryogenesis remains a mystery.
Positrons can also be produced by radioactive β+ decay, but this mechanism can occur both naturally and artificially.
Read more about this topic: Antimatter
Famous quotes containing the words artificial and/or production:
“These are not the artificial forests of an English king,—a royal preserve merely. Here prevail no forest laws but those of nature. The aborigines have never been dispossessed, nor nature disforested.”
—Henry David Thoreau (1817–1862)
“The production of obscurity in Paris compares to the production of motor cars in Detroit in the great period of American industry.”
—Ernest Gellner (b. 1925)