Dictionary
Thesaurus
Reference
Translate
Web
Electron electric dipole moment
1 reference results for: Electron electric dipole moment
Wikipedia
The electron electric dipole moment (EDM) d_e is, roughly speaking, a measure of the charge distribution within an electron. Within the standard model of elementary particle physics, such a dipole is predicted to be of smaller than 10^{-40} mathrm{ e cm}, where e stands for the elementary charge. The existence of a nonzero electron electric dipole moment would imply a violation of both parity invariance and time reversal invariance.

The Particle Data Group publishes its value as (.07±.07)×10−26e cm. The most recent experiment performed at the University of California at Berkeley placed an upper bound on (with a 90% confidence level) of |d_e| < 1.6 times 10^{-27} mathrm{e cm}.

Many extensions to the standard model have been proposed in the past two decades. These extensions generally predict larger values for the electron EDM. For instance, the various technicolor models predict |d_e| that ranges from 10^{-27} - 10^{-29}mathrm{e} mathrm{cm} . Supersymmetric models predict that |d_e| sim < 10^{-26} mathrm{e} mathrm{cm} ..

The present experimental limit is therefore close to eliminating some of these theories. Further improvements, or a positive result, would place further limits on which theory takes precedence.

References

Share This:Share This: digg.comShare This: ma.gnolia.comShare This: www.stumbleupon.comShare This: del.icio.usShare This: FacebookShare This: favorites.live.comShare This: www.technorati.comShare This: furl.netShare This: myweb2.search.yahoo.comShare This: www.google.com