Quantum chromodynamics: Difference between revisions
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In [[particle physics]], '''quantum chromodynamics''' (abbreviated as '''QCD''') is a specific kind of [[quantum field theory]] which supposes that [[fundamental particle]]s or [[hadron]]s (such as [[proton]]s and [[neutron]]s) are made up of [[quark]]s and [[gluon]]s which interact while they also have a kind of charge named "colour" (though this is not the same at all as real [[colour]]s). For the quarks, three colours are | In [[particle physics]], '''quantum chromodynamics''' (abbreviated as '''QCD''') is a specific kind of [[quantum field theory]] which supposes that [[fundamental particle]]s or [[hadron]]s (such as [[proton]]s and [[neutron]]s) are made up of [[quark]]s and [[gluon]]s which interact while they also have a kind of charge named "colour" (though this is not the same at all as real [[colour]]s). For the quarks, three colours are distinguished; red, green an blue. The "colour" of a quark's [[anti-particle]] partner is then known as anti-red, anti-green or anti-blue. [[Free particle]]s are combinations of these fundamental particles with no net colour. Examples of this are [[meson]]s which could then be described as a combination of a quark and an anti-quark, or [[baryon]]s which are according to QCD combinations of three quarks, one of each colour. Another specific property of QCD is that the force between the quarks increases as the distance between them becomes larger. This is known as [[asymptotic freedom]]. | ||
Since the 1950s, experimental tests have been carried out which have confirmed many aspects of QCD. | Since the 1950s, experimental tests have been carried out which have confirmed many aspects of QCD. | ||
Revision as of 05:51, 22 December 2010
In particle physics, quantum chromodynamics (abbreviated as QCD) is a specific kind of quantum field theory which supposes that fundamental particles or hadrons (such as protons and neutrons) are made up of quarks and gluons which interact while they also have a kind of charge named "colour" (though this is not the same at all as real colours). For the quarks, three colours are distinguished; red, green an blue. The "colour" of a quark's anti-particle partner is then known as anti-red, anti-green or anti-blue. Free particles are combinations of these fundamental particles with no net colour. Examples of this are mesons which could then be described as a combination of a quark and an anti-quark, or baryons which are according to QCD combinations of three quarks, one of each colour. Another specific property of QCD is that the force between the quarks increases as the distance between them becomes larger. This is known as asymptotic freedom.
Since the 1950s, experimental tests have been carried out which have confirmed many aspects of QCD.
References
- Hawking, S. & Mlodinow, L. The Grand Design: New Answers To The Ultimate Question of Life, Bantam Press, 2010.