Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Standard Model

  1. Apr 9, 2007 #1
    Could somebody please tell me a workable definition of the term "chiral theory" , and also explain its significance? As far as I know, in a chiral theory not all the fermions obtain a mass but whether this is a definition or a derived result is not clear to me. Thanks in advance
  2. jcsd
  3. May 4, 2007 #2
    As to me, the term "chiral" is associated with spinors. There are 2-spinors and 4-spinors. 2-spinors are also known as Weyl spinors or chiral spinors. 4-spinors are composed of 2-spinors and their Hermitian conjugates. 4-spinors are also known as Dirac spinors. See more details in my papers

  4. May 4, 2007 #3


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    The basic idea is the following. For spin 1/2 fermions, you may define separately left-handed and right-handed states. What I mean by this is that those are well-defined representations of the Lorentz group so they can be used as "building blocks" of a theory. A theory that treats differently the left-handed and right-handed states of the fermions is said to be chiral. By "treating" differently I mean that the terms in the lagrangian are not symmetric under exchanging the left and right handed spinors.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook