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friend
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Do you mean as opposed to quantum mechanics where particles have wave functions and observables?nikkkom said:All quantum field theories are like that.
Do you mean as opposed to quantum mechanics where particles have wave functions and observables?nikkkom said:All quantum field theories are like that.
But does each gluon convert the color of one quark? Or if a gluon is a superposition like,nikkkom said:But there is simply no basis where *all* eight gluons have a simple, "color+anticolor" form.
friend said:But does each gluon convert the color of one quark?
Yes, you seem to be arguing for a superposition of possible states in order to calculate numbers. But at the heart of each member of the superposition isn't there something that we can describe that is in superposition with other events we can describe? Isn't that what is meant be each interaction in the path integral. Electrons and positrons interact with photons is the basic interaction of the how these propagate. And then we add in other more complicated iterations of this. Likewise, in QCD isn't it the quarks interacting with gluons that we take as the basic interaction before considering superpositions? If so, then isn't there a list of which gluons interact with which quarks without complicating the question with superpositions (that would come after we define the basic interactions, right)?nikkkom said:That's a simplification, suitable when you are explaining QCD to a layman.
To get quantitatively precise results, you need to consider _all_ possible gluon emissions, with all permitted colors. And then take a weighted sum (integrate) over all these possibilities.
It seems to me that if you go around talking about electrons, positrons, and photons, before talking about propagation in the EM field, then for the same reason you should be just as able to talk about quarks and gluons. Are electrons and positron just for popular discussion?Orodruin said:Of course there is, but talking about them as rgb makes no real sense apart for the purposes of a popular discussion. Physicists do not go around talking about red, green and blue quarks. We use the appropriate mathematical framework to compute cross sections and decay rates.
How did you get that from what I said?friend said:It seems to me that if you go around talking about electrons, positrons, and photons, before talking about propagation in the EM field, then for the same reason you should be just as able to talk about quarks and gluons. Are electrons and positron just for popular discussion?
It sounds like we are avoiding talking about the ontology of unobservables, again, because quarks and gluons are not directly observable, though electrons and positrons are observable. Tell me, do we have just as much trouble talking about the properties of W-, W+, and Z0 boson? For those aren't directly observable either as I recall, since their half-life is 3*10-25s.Orodruin said:How did you get that from what I said?
I appreciate your efforts. So I'm looking for how gluons interact with quarks. I've seen a basis showing a combination of color and anticolor for each gluon. And I'm trying to visualize which gluons interact with which quarks. I've been told that a quark of a particular color can change that color by emitting a gluon. And likewise they can change their color by absorbing a gluon. But the labels I've seen so far on the gluons suggest that they interact with quarks of a certain color. So instead of every gluon interacting with every quark, the labeling suggest that there are restrictions on the kinds of interaction. Is there a simple list or table stating, for example, that this gluon interacts with these quarks an no others, etc? Thanks.nikkkom said:SU(3) gauge symmetry of quarks says that you can look at them as having r,g,b charges; _and also_, you can look at them as having charges in any other valid basis of "color space".
Same goes for gluons.
For quarks, "r,g,b basis" looks easy and natural.
Gluons don't have a "nice looking" basis. Sorry. Complain to the gods of group theory.
friend said:I appreciate your efforts. So I'm looking for how gluons interact with quarks. I've seen a basis showing a combination of color and anticolor for each gluon. And I'm trying to visualize which gluons interact with which quarks. I've been told that a quark of a particular color can change that color by emitting a gluon.
OK I can accept that. It's like expressing a wave function in various basis but the operator math is still the same.nikkkom said:IOW: you can repaint any quark however you want, including any complex superposition of colors (as long as they add up to 1).
I think not. (That was probably a stupid question.) For if that were the case, then it would be impossible to enumerate various kinds of gluons. They would be indistinguishable. In fact, aren't the gluons specifically distinguished from each other by the fact that they interact with quarks differently?friend said:Does every gluon interact with every quark?