physics Physics is the scientific study of matter, its Elementary particle, fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge whi ...

, a dyon is a

hypothetical particle This is a list of known and hypothesized microscopic particles in particle physics, condensed matter physics and cosmology. Standard Model elementary particles Elementary particles are particles with no measurable internal structure; that is, ...

in 4-dimensional theories with both

electric Electricity is the set of physical phenomena associated with the presence and motion of matter possessing an electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as described by Maxwel ...

and

magnetic Magnetism is the class of physical attributes that occur through a magnetic field, which allows objects to attract or repel each other. Because both electric currents and magnetic moments of elementary particles give rise to a magnetic field, m ...

charges. A dyon with a zero

electric charge Electric charge (symbol ''q'', sometimes ''Q'') is a physical property of matter that causes it to experience a force when placed in an electromagnetic field. Electric charge can be ''positive'' or ''negative''. Like charges repel each other and ...

is usually referred to as a

magnetic monopole In particle physics, a magnetic monopole is a hypothetical particle that is an isolated magnet with only one magnetic pole (a north pole without a south pole or vice versa). A magnetic monopole would have a net north or south "magnetic charge". ...

. Many

grand unified theories A Grand Unified Theory (GUT) is any model in particle physics that merges the electromagnetic, weak, and strong forces (the three gauge interactions of the Standard Model) into a single force at high energies. Although this unified force has ...

predict the existence of both magnetic monopoles and dyons. Dyons were first proposed by

Julian Schwinger Julian Seymour Schwinger (; February 12, 1918 – July 16, 1994) was a Nobel Prize-winning American theoretical physicist. He is best known for his work on quantum electrodynamics (QED), in particular for developing a relativistically invariant ...

in 1969 as a phenomenological alternative to quarks. He extended the Dirac quantization condition to the dyon and used the model to predict the existence of a particle with the properties of the

J/ψ meson The (J/psi) meson is a subatomic particle, a flavor-neutral meson consisting of a charm quark and a charm antiquark. Mesons formed by a bound state of a charm quark and a charm anti-quark are generally known as " charmonium" or psions. The ...

prior to its discovery in 1974. The allowed charges of dyons are restricted by the Dirac quantization condition. This states in particular that their magnetic charge must be integral, and that their electric charges must all be equal modulo 1. The Witten effect, demonstrated by

Edward Witten Edward Witten (born August 26, 1951) is an American theoretical physics, theoretical physicist known for his contributions to string theory, topological quantum field theory, and various areas of mathematics. He is a professor emeritus in the sc ...

in his 1979 paper, states that the electric charges of dyons must all be equal, modulo one, to the product of their magnetic charge and the theta angle of the theory. In particular, if a theory preserves CP symmetry then the electric charges of all dyons are

integer An integer is the number zero (0), a positive natural number (1, 2, 3, ...), or the negation of a positive natural number (−1, −2, −3, ...). The negations or additive inverses of the positive natural numbers are referred to as negative in ...

References

External links

* {{cite journal , last1=Chanyal , first1=B. C. , last2=Bisht , first2=P. S. , last3=Negi , first3=O. P. S. , title=Generalized Octonion Electrodynamics , journal=International Journal of Theoretical Physics , volume=49 , issue=6 , date=1 March 2010 , issn=0020-7748 , doi=10.1007/s10773-010-0314-5 , pages=1333–1343, arxiv=0910.1451 , bibcode=2010IJTP...49.1333C , s2cid=118377495
Electromagnetic duality for children
lecture notes by José Figueroa-O'Farrill Gauge theories Magnetic monopoles Physics beyond the Standard Model