electroweak theory, a unified field theory that describes two of the fundamental forces in nature, electromagnetism (see electromagnetic radiation electromagnetic radiation, energy radiated in the form of a wave as a result of the motion of electric charges. A moving charge gives rise to a magnetic field, and if the motion is changing (accelerated), then the magnetic field varies and in turn produces an
..... Click the link for more information. ) and the weak interaction weak interactions, actions between elementary particles mediated, or carried, by W and Z particles and that are responsible for nuclear decay. Weak interactions are one of four fundamental interactions in nature, the others being gravitation , electromagnetism, and
..... Click the link for more information. . The electroweak theory derived from efforts to produce a theory for the weak force analogous to quantum electrodynamics quantum electrodynamics (QED), quantum field theory that describes the properties of electromagnetic radiation and its interaction with electrically charged matter in the framework of quantum theory .
..... Click the link for more information. (QED), the quantum theory of the electromagnetic force. Although the weak force fails to meet a requirement for that theory—that it behave the same way at different points in space and time—because it acts only across distances smaller than an atomic nucleus, it was shown that the electromagnetic force, which can extend across interstellar distances, and the weak force are but different manifestations of a more fundamental force, the electroweak force. This made it possible to formulate a unified model that predicted the existence of mediating, or messenger, particles. The electroweak theory, for which Sheldon Glashow Glashow, Sheldon Lee (glăsh`ō), 1932–, American physicist, b. New York City, Ph.D. Harvard, 1959.
..... Click the link for more information. , Abdus Salam Salam, Abdus, 1926–96, Pakistani physicist. After attending Government College at Lahore, he received a Ph.D. from Cambridge (1952). He taught in Lahore for three years before returning to England, first teaching mathematics at Cambridge (1954–57), then
..... Click the link for more information. , and Steven Weinberg Weinberg, Steven, 1933–, American nuclear physicist, b. New York City, Ph.D. Princeton Univ., 1957. He helped develop important theories of electromagnetic and nuclear particle interaction that were experimentally verified in 1982–83 when Carlo Rubbia and
..... Click the link for more information. shared the 1979 Nobel Prize in Physics, was confirmed in 1983 by the discovery of the W and Z particles W and Z particles, elementary particles that mediate, or carry, the fundamental force associated with weak interactions . The discovery of the W and Z
..... Click the link for more information. , two of a number of elementary particles elementary particles, the most basic physical constituents of the universe.

Basic Constituents of Matter

Molecules are built up from the atom , which is the basic unit of any chemical element .
..... Click the link for more information. it predicted.

Bibliography

See P. Renton, Electroweak Interactions (1990); J. Horejsi, Introduction to Electroweak Unification (1994); A. Salam, Selected Papers of Abdus Salam (1994); J. D. Walecka, Theoretical Nuclear and Subnuclear Physics (1995).

electroweak theory

Theory that describes both the electromagnetic force and the weak force. Though the forces appear to be different, they are actually different facets of a more fundamental force. This theory, formulated in the 1960s by Sheldon Glashow (born 1932), Steven Weinberg (born 1933), and Abdus Salam (born 1926), represents a 20th-century scientific landmark and won its authors a 1979 Nobel Prize. It was validated in the 1980s with the discovery of the W particle and Z particle, which it had predicted. See also fundamental interaction, unified field theory.