Portions of this entry contributed by Leonardo Motta
Portions of this entry contributed by Bhuvanesh Bhatt
In order to visualize and describe quantum electrodynamical interactions, physicist Richard P. Feynman Eric Weisstein's World of Biography introduced an ingenious schematic form of drawing now called a Feynman diagram. In such a diagram, all particles are represented by lines, with straight lines representing fermions and wavy lines representing bosons (except for the Higgs boson, which is usually represented by a dashed line, and gluons, which are usually represented by loops).
Particles entering or leaving a Feynman diagram correspond to real particles, while intermediate lines represent virtual
particles. Real particles must satisfy the energy-momentum relation
The diagram illustrated above represents the interaction of two electrons. Each electron is represented by a straight line, which exchange a (virtual) photon and then repel one other.
Fine Structure Constant, Quantum Electrodynamics
References
Berestetskii, V. B.; Lifschitz, E. M.; and Pitaevskii, L. P. Quantum Electrodynamics, 2nd ed. Oxford, England: Pergamon Press, 1982.
Feynman, R. P. "Space-Time Approach to Quantum Electrodynamics." Phys. Rev. 76, 769-789, 1949.
Feynman, R. P. QED: The Strange Theory of Light and Matter. Princeton, NJ: Princeton University Press, 1985.
Griffiths, D. Introduction to Elementary Particles. New York: Wiley, 1987.
Johnson, G. W. and Lapidus, M. L. The Feynman Integral and Feynman's Operational Calculus. Oxford, England: Oxford University Press, 2000.
Kane, G. The Particle Garden. Reading, MA: Addison-Wesley, p. 169, 1995.
Mattuck, R. D. A Guide to Feynman Diagrams in the Many-Body Problem, 2nd ed. New York: Dover, 1992.
Weisstein, E. W. "Books about Feyman Diagrams." http://www.ericweisstein.com/encyclopedias/books/FeynmanDiagrams.html.
