Chiral SymmetrySee also: Chiral symmetry
Vector gauge theories with massless Dirac fermion fields exhibit chiral symmetry, i.e., rotating the left-handed and the right-handed components independently makes no difference to the theory. We can write this as the action of rotation on the fields:
With N flavors, we have unitary rotations instead: SU(N)L×SU(N)R.
Massive fermions do not exhibit chiral symmetry. One also says that the mass term in the Lagrangian, breaks chiral symmetry explicitly. Spontaneous chiral symmetry breaking may also occur in some theories, most notably in quantum chromodynamics.
Read more about this topic: Chirality (physics)
Other articles related to "chiral, chiral symmetry, symmetry":
... His focus was to separate the chiral breaking and confinement scales, but he also noted that such a theory could enhance and thus allow the ETC scale to be raised ... enough (> αχ SB) to break spontaneously the massless technifermions' chiral symmetry ... point value αIR, and the strength αχ SB necessary for chiral symmetry breaking depend on the particular renormalization scheme adopted ...
... This symmetry of the Lagrangian is called flavor symmetry or chiral symmetry, and denoted as ... It can be decomposed into The vector symmetry acts as and corresponds to baryon number conservation ... The axial symmetry acts as and it does not correspond to a conserved quantity because it is violated due to quantum anomaly ...
... it attributes the lightness of the pions as an accident rather than a result of chiral symmetry breaking ... be thought of as the gauge bosons of a spontaneously broken gauge symmetry whose local character is emergent (arising from QCD) Note that this broken gauge symmetry (sometimes called hidden local symmetry ... described by Howard Georgi in a paper titled "The Vector Limit of Chiral Symmetry" where he ascribed much of the literature of hidden local symmetry to a non-linear ...
... Chiral symmetry breaking is an example of spontaneous symmetry breaking affecting the chiral symmetry of the strong interactions in particle physics ... Nambu–Goldstone bosons in this spontaneous symmetry breaking process are the pions, whose mass is an order of magnitude lighter than the mass of the ... significant ingredient of the Higgs mechanism underlying the electroweak symmetry breaking ...
Famous quotes containing the word symmetry:
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