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B Gluon Color Question

  1. Mar 12, 2016 #1
    if "color" is one of the eigenvalues, how may a single gluon be in possession of 2 of them and still be unique?

    also, a 2-color gluon is reminiscent of a 2-color tao, no?
     
  2. jcsd
  3. Mar 12, 2016 #2

    mfb

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    Gluons have a color and an anti-color, I don't see the problem. What do you mean by "be unique"?
    I don't understand that question.
     
  4. Mar 12, 2016 #3
    somehow it seems that distinct 'colors' should not be hyphenated to be used as lables for naming gluons, because the eigen-value for, say, green-ness communicates the quality of that color-charge which we call green, and which is, in spirit, orthogonal to the other unique color-charge qualities. if then, say, anti-blue is added to the mix, it brings its own distinct quality. with two qualities to identify, it seems that we would need to use two eigen-values, but by convention, we use only one. we do this by hyphenating the two color-charge qualities and considering their combination to be a label for this gluon. does that make sense?
     
  5. Mar 12, 2016 #4
    as far as the gluon and the yinyang, they look similar, i think, because i picture them as having two halves of different colors
     
  6. Mar 12, 2016 #5
    i think of this kind of logic as "failed fourth" because it feels like we've identified a valid trivision of the concept of color-charge, but then have somehow lost the essence of that when we put two color charge qualities into a single eigen-value for the purpose of creating a label.
     
  7. Mar 12, 2016 #6
    in a way, it feels like we don't need the quarks because all of the information is inherent in the gluons, which are di-vided but communicate tri-vision, and therefore speak the languages of both two-ness and three-ness of which the world is made.
     
  8. Mar 12, 2016 #7

    mfb

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    No it does not.
    It is not.
    That does not make sense at all.


    Please start with a textbook to learn the actual science before you start wildly speculating. Speculation without knowledge is pointless. You miss all the experimental evidence that has been collected for example.
     
  9. Mar 12, 2016 #8
    thank you
     
  10. Mar 14, 2016 #9
  11. Mar 23, 2016 #10
    are the transitions described by gluons thought to occur in any particular sequence? for example, perhaps a blue quark turning into a red quark is always followed next by a red quark turning into a green quark.
     
  12. Mar 23, 2016 #11

    mfb

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    No. You cannot even say "it was a blue quark that turned into a red quark" because quantum mechanics makes that statement meaningless.
     
  13. Mar 23, 2016 #12
    i think i follow what you mean, mfb, but within the languaging of QM, might it still not be possible to posit one or more sequences in which a given color-charge process is more likely to be followed by a second one than its by its peers. as a start, is there any basis upon which to posit that "color 1 quark having become color 2 quark, it is more likely that the next process is not a reversal back to color 1"?
     
  14. Mar 23, 2016 #13
    the reason i ask about this is that i've developed a transition sequence in another model i'm playing with, and wondering if the idea of a preferred sequence might also apply to quarks and their color-changing.
     
  15. Mar 23, 2016 #14

    Vanadium 50

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    We don't develop personal theories here.
    Quantum mechanics does not allow what you are describing.
    One reason we don't develop personal theories here is when people are told, "No, that's not how the universe behaves" they want to argue about it.
     
  16. Mar 23, 2016 #15

    ohwilleke

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    A few points:

    1. We know there are three color charges in QCD but our assignment of a particular color to particular quarks and gluons in a particular interaction is entirely arbitrary and is also purely a theoretical construct. The particular color charge of a particular quark, or of a particular gluon, is not an observable. It is an intermediate step which when used to define which possible future paths of quarks and gluons are possible produces the right probabilities of observable end states. One of the hints that these intermediate steps are "real" is that you need to consider not just quark-gluon-quark chains of interaction, but also gluon-gluon interactions, to make accurate QCD calculations.

    2. One of the main consequences of there being three colors is that baryons are composed of three quarks or three anti-quarks that are confined, while mesons are confined in quark-antiquark pairs (free quarks are not observed). A corollary of this reality is that all hadrons have integer electric charges despite the fact that quarks are inferred to have electric charges of +/- 1/3 or +/- 2/3, which is convenient because this means that leptons (all of which have integer electric charges) associate in whole number quantities with atomic nuclei. Another consequence of this is that any particular quark is three times as likely to be produced in the weak force decay of a W or Z boson (at tree level) as a particular lepton is to be produced in that decay (subject to conservation of mass-energy limitations).

    3. The observable properties of each color and each gluon color charge combination is identical to the the observable property of every other color and gluon color charge combination respectively. The important thing is the number of distinct possibilities that are not identical to each other, not the distinctions between the properties of one state and another. For example, the magnitude of the color charge of every gluon is exactly identical, and the magnitude of the color charge of every quark is identical.

    4. The convention of identifying gluons in color-anticolor format is somewhat misleading, because there are actually only eight, rather than nine possible gluon configurations, given the way that color charge is defined in the relevant SU(3) algebraic group. For some purposes, heuristically (i.e. for purposes of understanding as opposed to an accurate description of reality or the equations), it can be helpful to think of gluons as a set of three toggle switches each of which can be in an on or off position (for which there are eight configurations), instead of as color-anticolor pairs (for which you would naively expect there to be nine configurations which is not the number of configurations that correctly reproduces the probabilities of outcomes we observe when we do calculations that involve gluons).

    A good place to start to understand quarks and gluons is to read the final chapter of Richard Feyman's short book "QED" which explains all of this quite clearly with minimal advanced mathematics.
     
    Last edited: Mar 23, 2016
  17. Mar 23, 2016 #16
    thank you both, gentlemen, for educating me in site policies and QCD respectively. i admit that i am a personal theorist, and that this is not the place for me, but so far i've been unable to find the right affinity group for me. all i know is that in QCD, just as in the Big Bang Theory, the DI-vision of reality into matter vs antimatter defines 2ness itself in the physical world, even while the TRI-vision of reality into 3 types of quarks defines 3ness itself in the physical world, and that it's useful to have a rich understanding of 2ness and 3ness. these are the types of 'micro-insights' that are obvious to me, but i just have to find the right people to share them with.
    Sirs, i shall withdraw my presence for the time. i feel that my exit this time is a little more humane than in the past, so thank you very much for that.
     
  18. Mar 23, 2016 #17

    mfb

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    That does not make sense at all.

    If you want to do something useful related to QCD, I suggest to get a textbook. To develop new theories, you first have to understand all the experimental data that has been collected over the last decades. Otherwise every "theory" will be completely incompatible with experimental data, and completely pointless.

    I think this thread is done.
     
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