Talk:Quantum chromodynamics

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Challenges to QCD by others[edit]

I can see that there are a number of experts here on the whole topic of QCD and perhaps someone can comment - either here in the discussion or possibly integrated in the body of the article itself - regarding some criticism of QCD that I read about rather recently in a book. The author is trying to present a new theory based on magnetic monopoles (not Dirac monopoles) rather than the Quark-Gluon / color-charge model of QCD, and in the process presents a number of compelling questions about QCD, including (just paraphrasing from what I remember from the book):

  • the rise of cross-section for both elastic and inelastic proton-proton scattering
  • charge density of the neutron
  • tensor force in neucleons
  • the presence and location of additional quark-antiquark pairs
  • There was also some mathematic proof about gordon-klein (?) being inconsistant
  • proton spin crisis
  • the fact that the color force is the reverse of all other forces in nature (where the intensity diminishes with the distance or a power thereof- rather than getting stronger when quarks are separated)
  • the lack of finding of any particles predicted by QCD like 4-quark, 5-quark, glueballs, etc.

I don't have much of a background in physics at all- I just stumbled on the book at one point and recall that he made a compelling argument against QCD and for his own monopole model, which he claims - quite convincingly- answers all of the questions that he raised against QCD. Frankly, I think that it would be great if we could collect all of the arguments (with refutations) in either a section of the article or in a separate article. Any thoughts would be welcome and appreciated. Thanks, Michael. (talk) 18:50, 11 May 2012 (UTC)

Mathematical Model[edit]

As far as I understand this, these are principal fibre bundles on a space-time base space. The fibres in the electrodynamical case are SU(1) (i.e. the unity circle) with sections the electrodynamical vector potentials; In chromodynamics they are SU(3), the sections being tensor potentials with values in complex three-dimensional space, the self-representation of SU(3). So there are three principal fibre bundles: Besides these two there is the tangent (or cotangent) bundle, in which general relativity takes place. If that is so, there is the question: What changes if we change the base space from one cosmological model to another? And how fits unification and grand unification into these mathematical structures? Local symmetries are invariance transformations in the tangent bundle, global ones are transformations in the whole multi-dimensional manifold. — Preceding unsigned comment added by (talk) 10:35, 28 July 2012 (UTC)

New article gluon field and a QCD question[edit]

I split content from gluon field strength tensor to gluon field because the two fields are different, and there is lots of literature on these fields, so maybe separate articles could develop the mathematics carefully. We have electromagnetic four-potential and electromagnetic tensor, so why not similarly for the strong interaction? If there are strong (excuse pun) opinions to explain the fields together (as it happened with position and momentum space) then we can always merge.

Concerning the section quantum chromodynamics#Lagrangian: the \tilde{\mathbf{G}} seems to be exactly the same as \mathcal{A} for the gluon field, so I'm changing the notation, just as an IP did here. Posting here to for others to comment in advance.

Thanks for any corrections highlighted in advance. M∧Ŝc2ħεИτlk 21:57, 16 October 2013 (UTC)

Transplant of curvature 2-form expression from this article to gluon field strength tensor[edit]

See this cut and paste. This article gives the tensor expression for the Lagrangian and the gluon field strength:

G^a_{\mu \nu} = \partial_\mu \mathcal{A}^a_\nu - \partial_\nu \mathcal{A}^a_\mu + g f^{abc} \mathcal{A}^b_\mu \mathcal{A}^c_\nu \,,

which is enough - we don't need the differential forms... M∧Ŝc2ħεИτlk 21:18, 20 October 2013 (UTC)