User:John R. Brews/Sample
In physics and chemistry, charge is a fundamental property of matter that causes a force of attraction to (or repulsion from) spatially separate matter that likewise manifests the property of charge. Classically, two types of charge are known, magnetic and electric. The distinguishing property of electric charge is that electric charges can be isolated, while while an isolated magnetic charge or magnetic monopole never has been observed.[1][2][3][4] Electric charges interact with magnetic charges only when in relative motion one to the other.
In the physics of quantum chromodynamics, the successor to quantum elecrodynamics, color charge is recognized as a property of quarks.[5] Similar to magnetic charge, color is not seen directly, as all observable particles have no overall color.[6] Color charge causes interaction between charged entities via the chromoforce, also called the color force. As with electric and magnetic charge, color charge can be multiple valued, conventionally called red, green or blue. Color charge is not assigned a numerical value; however, a superposition in equal amounts of all three colors leads to a "neutral" color charge, a somewhat stretched analogy with the superposition of red, green and blue light to produce white light.[7] Thus, protons and neutrons, which consist of three quarks with all three colors are color-charge neutral. Quark combinations are held together by exchange of combinations of eight different gluons that also are color charged.[8][9][10][11]
The color charges of antiquarks are anticolors. The combination of a quark and an antiquark to form a meson, such as a pion, kaon and so forth, leads to a neutral color charge.
Another charge in elementary particle theory is the baryonic charge, with value +1 for all baryons and −1 for all antibaryons.
Finally, we mention the leptonic charge carried by electrons and neutrinos.[7]
References
- ↑ Douglas C. Giancoli. Physics for scientists and engineers with modern physics, 4rth ed. Pearson Education, p. 708. ISBN 0132273594.
- ↑ Gibilisco S. (2005). “Chapter 2: Charge, current, voltage”, Electricity Demystified. McGraw-Hill. ISBN 0071439250. An entry level account by Stan Gibilisco, an electronics engineer and mathematician, author of numerous technical books on electronics and mathematics.
- ↑ Glenn Elert (1998-2010). The electric charge: Summary. The Physics Hypertextbook. Retrieved on 2011-07-27.
- ↑ Glenn Elert (1998-2010). The electric charge: Discussion. The Physics Hypertextbook. Retrieved on 2011-07-27.
- ↑ Stephen Webb (2004). Out of this world: colliding universes, branes, strings, and other wild ideas of modern physics. Springer, p. 190. ISBN 0387029303.
- ↑ Andrew Watson (2004). The quantum quark. Cambridge University Press, pp. 170 ff. ISBN 0521829070.
- ↑ 7.0 7.1 M. Y. Han (1999). Quarks and gluons: a century of particle charges. World Scientific, p. 116. ISBN 9810237456.
- ↑ Joe Rosen (2004). Encyclopedia of physics. Infobase Publishing, p. 85. ISBN 0816049742.
- ↑ Joe Rosen, Lisa Quinn Gothard (2009). Encyclopedia of Physical Science, Volume 1. Infobase Publishing, p. 278. ISBN 0816070113.
- ↑ (2009) “Quantum chromodynamics (QCD)”, Daniel M. Greenberger, Klaus Hentschel, Friedel Weinert: Compendium of Quantum Physics: Concepts, Experiments, History and Philosophy. Springer, pp. 524 ff. ISBN 3540706224.
- ↑ OW Greenberg (2008). "The color charge degree of freedom in particle physics". Chapter in Greenberger et al. below.