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

B About CPT symmetry

  1. Oct 12, 2016 #1
    Some books prove CPT theorem basing on scalars,vectors, tensors building from 4-spinor of fermion and gamma matrices.Why can they do that?Because a general Lagrangian can contain bose scalar,bose vector,bose tensor fields and spinor fields.
    The CPT theorem says CPT symmetry is a strictly correct.What about the PT symmetry,is it also strictly correct because it is Lorentz transformation?
     
  2. jcsd
  3. Oct 13, 2016 #2

    vanhees71

    User Avatar
    Science Advisor
    2016 Award

    In Weinberg, Quantum Theory of Fields, vol. 1 you find a proof for fields of arbitrary spin.

    Then you should note that Lorentz invariance (or better Poincare) invariance refers to the continuous part of the Poincare group connected with the identity, i.e., the semidirect product of space-time translations with the proper orthochronous Lorentz group ##\mathrm{SO}(1,3)^{\uparrow}##. Poincare invariance just dictates invariance under this group due to the spacetime structure of special relativity. There's no need a priori that the theory should be invariant under any of the discrete transformations ##P##, ##T##, and ##C##. The ##CPT## theorem, however, tells you that any local relativistic QFT with a stable ground state (Hamiltonian bounded from below) is also automatically symmetric under ##CPT##. In the Standard Model all other combinations are violated by the weak interaction, and this is experimentelly checked for each of them, i.e., nature is not symmetric under each of the transformations ##P## (e.g., Wu experiment), ##CP## (neutral-kaon system, Cronin&Fitch), ##T## (I forgot who did the independent experimental proof on some B decays first; it was some recent LHC experiment).
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: About CPT symmetry
  1. About symmetry (Replies: 2)

Loading...