Concept

Electron electric dipole moment

The electron electric dipole moment de is an intrinsic property of an electron such that the potential energy is linearly related to the strength of the electric field: The electron's electric dipole moment (EDM) must be collinear with the direction of the electron's magnetic moment (spin). Within the Standard Model of elementary particle physics, such a dipole is predicted to be non-zero but very small, at most 10−38 e⋅cm, where e stands for the elementary charge. The discovery of a substantially larger electron electric dipole moment would imply a violation of both parity invariance and time reversal invariance. In the Standard Model, the electron EDM arises from the CP-violating components of the CKM matrix. The moment is very small because the CP violation involves quarks, not electrons directly, so it can only arise by quantum processes where virtual quarks are created, interact with the electron, and then are annihilated. If neutrinos are Majorana particles, a larger EDM (around e-33e⋅cm) is possible in the Standard Model. 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 that ranges from 10−27 to 10−29 e⋅cm. Some supersymmetric models predict that > 10−26 e⋅cm but some other parameter choices or other supersymmetric models lead to smaller predicted values. The present experimental limit therefore eliminates some of these technicolor/supersymmetric theories, but not all. Further improvements, or a positive result, would place further limits on which theory takes precedence. As the electron has a net charge, the definition of its electric dipole moment is ambiguous in that depends on the point about which the moment of the charge distribution is taken. If we were to choose to be the center of charge, then would be identically zero. A more interesting choice would be to take as the electron's center of mass evaluated in the frame in which the electron is at rest.

About this result
This page is automatically generated and may contain information that is not correct, complete, up-to-date, or relevant to your search query. The same applies to every other page on this website. Please make sure to verify the information with EPFL's official sources.
Related courses (4)
PHYS-201(d): General physics: electromagnetism
The topics covered by the course are concepts of fluid mechanics, waves, and electromagnetism.
PHYS-201(c): General physics : electromagnetism
Introduction à la mécanique des fluides, à l'électromagnétisme et aux phénomènes ondulatoires.
PHYS-114: General physics : electromagnetism
Le cours traite des concepts de l'électromagnétisme, avec le support d'expériences. Les sujets traités inclus l'électrostatique, le courant électrique et circuits, la magnétostatique, l'induction élec
Show more
Related lectures (29)
Capacitance and Dielectrics: Fundamentals
Covers the fundamental concepts of capacitance, dielectrics, and polarization mechanisms in materials.
Magnetic Moments and Material Properties
Covers magnetic dipole moments, atomic currents, material properties, and bound charges.
Photon: Emission of Waves
Covers the concept of a photon, its emission, coherence length, and the electromagnetic spectrum.
Show more
Related publications (39)

Interfacial Water Many-Body Effects Drive Structural Dynamics and Allosteric Interactions in SARS-CoV-2 Main Protease Dimerization Interface

Frédéric Célerse, Théo Pierre Jaffrelot Inizan

Following our previous work (Chem. Sci. 2021, 12, 4889-4907), we study the structural dynamics of the SARS-CoV-2 Main Protease dimerization interface (apo dimer) by means of microsecond adaptive sampling molecular dynamics simulations (50 mu s) using the A ...
AMER CHEMICAL SOC2021

Predicting molecular dipole moments by combining atomic partial charges and atomic dipoles

Michele Ceriotti, David Mark Wilkins, Max David Veit, Yang Yang

The molecular dipole moment (mu) is a central quantity in chemistry. It is essential in predicting infrared and sum-frequency generation spectra as well as induction and long-range electrostatic interactions. Furthermore, it can be extracted directly-via t ...
AMER INST PHYSICS2020

Predicting molecular dipole moments by combining atomic partial charges and atomic dipoles

Michele Ceriotti, David Mark Wilkins, Max David Veit

The molecular dipole moment (mu) is a central quantity in chemistry. It is essential in predicting infrared and sum-frequency generation spectra as well as induction and long-range electrostatic interactions. Furthermore, it can be extracted directly-via t ...
2020
Show more
Related concepts (5)
Electric dipole moment
The electric dipole moment is a measure of the separation of positive and negative electrical charges within a system, that is, a measure of the system's overall polarity. The SI unit for electric dipole moment is the coulomb-meter (C⋅m). The debye (D) is another unit of measurement used in atomic physics and chemistry. Theoretically, an electric dipole is defined by the first-order term of the multipole expansion; it consists of two equal and opposite charges that are infinitesimally close together, although real dipoles have separated charge.
CP violation
In particle physics, CP violation is a violation of CP-symmetry (or charge conjugation parity symmetry): the combination of C-symmetry (charge symmetry) and P-symmetry (parity symmetry). CP-symmetry states that the laws of physics should be the same if a particle is interchanged with its antiparticle (C-symmetry) while its spatial coordinates are inverted ("mirror" or P-symmetry). The discovery of CP violation in 1964 in the decays of neutral kaons resulted in the Nobel Prize in Physics in 1980 for its discoverers James Cronin and Val Fitch.
T-symmetry
T-symmetry or time reversal symmetry is the theoretical symmetry of physical laws under the transformation of time reversal, Since the second law of thermodynamics states that entropy increases as time flows toward the future, in general, the macroscopic universe does not show symmetry under time reversal. In other words, time is said to be non-symmetric, or asymmetric, except for special equilibrium states when the second law of thermodynamics predicts the time symmetry to hold.
Show more

Graph Chatbot

Chat with Graph Search

Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.

DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.