Chiral gauge theory

Chiral gauge theory

In quantum field theory, a chiral gauge theory is a quantum field theory with charged chiral (i.e. Weyl) fermions. For instance, the Standard Model is a chiral gauge theory. For topological reasons, chiral charged fermions cannot be given a mass without breaking the gauge symmetry, which will lead to inconsistencies unlike a global symmetry. It is notoriously difficult to construct a chiral gauge theory from a theory which does not already contain chiral fields at the fundamental level.[1] A consistent chiral gauge theory must have no gauge anomaly (or global anomaly). Almost by necessity, regulators will have to break the gauge symmetry. This is responsible for gauge anomalies in the first place.

Contents

Fermion doubling on a lattice

Lattice regularizations suffer from fermion doublings leading to many tastes, and a loss of chirality.

3-4-5 model

The simplest model has 1 spatial and 1 time dimension. We have a U(1) gauge symmetry. There are left-mover chiral fermions with charges ± 3 and ±; 4. We have a right-mover with charge ± 5. This is a Pythagorean triple. This theory is free from gauge anomalies.

See also

References

  1. ^ Ball, "Chiral Gauge Theory," [1]

External links



Wikimedia Foundation. 2010.

Игры ⚽ Нужно сделать НИР?

Look at other dictionaries:

  • Gauge theory — For a generally accessible and less technical introduction to the topic, see Introduction to gauge theory. In physics, a gauge theory is a type of field theory in which the Lagrangian is invariant under a continuous group of local transformations …   Wikipedia

  • Supersymmetric gauge theory — mathcal{N}=1 SUSY in 4D (with 4 real generators) = In theoretical physics, one often analyzes theories with supersymmetry which also haveinternal gauge symmetries. So, it is important to come up with a supersymmetric generalizationof gauge… …   Wikipedia

  • Introduction to gauge theory — This article is an accessible, non technical introduction to the subject. For the main encyclopedia article, see Gauge theory. Quantum field theory …   Wikipedia

  • Gauge anomaly — In theoretical physics, a gauge anomaly is an example of an anomaly: it is an effect of quantum mechanics usually a one loop diagram that invalidates the gauge symmetry of a quantum field theory; i.e. of a gauge theory. Anomalies in gauge… …   Wikipedia

  • Chiral symmetry breaking — In particle physics, chiral symmetry breaking is an example of spontaneous symmetry breaking affecting the chiral symmetry of gauge theory such as Quantum Chromodynamics. The origin may be described as a fermion condensate (vacuum condensate of… …   Wikipedia

  • Chiral anomaly — A chiral anomaly is the anomalous nonconservation of a chiral current. In some theories of fermions with chiral symmetry, the quantization may lead to the breaking of this (global) chiral symmetry. In that case, the charge associated with the… …   Wikipedia

  • Chiral color — In particle physics phenomenology, chiral color is a speculative model[1] which extends quantum chromodynamics (QCD), the generally accepted theory for the strong interactions of quarks. QCD is a gauge field theory based on a gauge group known as …   Wikipedia

  • Mirror symmetry (string theory) — In physics and mathematics, mirror symmetry is a relation that can exist between two Calabi Yau manifolds. It happens, usually for two such six dimensional manifolds, that the shapes may look very different geometrically, but nevertheless they… …   Wikipedia

  • String theory — This article is about the branch of theoretical physics. For other uses, see String theory (disambiguation). String theory …   Wikipedia

  • Grand unification theory — articleissues article=y refimprove=June 2006 expert=Physics tone=August 2008 update=March 2008Grand Unification, grand unified theory, or GUT refers to any of several very similar unified field theories or models in physics that predicts that at… …   Wikipedia

Share the article and excerpts

Direct link
… Do a right-click on the link above
and select “Copy Link”