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Thread: are quarks "inseperable"?

  1. #1 are quarks "inseperable"? 
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    I heard that the strong force which holds the quarks together in protons and neutrons is unbreakable. That is, one cannot tear the quarks in, say, a proton apart no matter how hard one tries. Is this true? If it is, then how did scientists ever figure out that protons and neutrons were made of quarks (AFAIK scientists figure out what a particle is made of by breaking it apart in an accelerator)?


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    Administrator KALSTER's Avatar
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    I guess because it is not unbreakable? Very strong though.
    It was done in particle accelerators. They accelerate particles in opposite directions and crash them into each other, and then they come apart.


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    WYSIWYG Moderator marnixR's Avatar
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    as far as i'm aware none of the particle accelerator experiments have managed to produce a naked quark
    what did happen though is that entities were observed that were best explained as consisting of 2 quarks, whereas protons and neutrons are made up of 3
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    Forum Senior TvEye's Avatar
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    I assume this is an elementary question, but can anyone describe the process of observing a quark?
    "First we build the tools, then they build us" - Marshall McLuhan.
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    The phraze "cloud chamber" comes to mind, but not exactly sure what it is.
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    When a strong force bond is stretched beyond it's point of...stability (can't really say breaking), the pair of quarks actually duplicates, forming another pair of quarks with a strong force mediated bond between them. That's how it is with mesons at least. It must be the same for baryons, though I can't say if it simply forms another baryone or what.
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    Oh yeh, here you go. The bubble chambers, among others uses, are used deep underground to detect neutrinos, if I'm not mistaken.
    http://en.wikipedia.org/wiki/Cloud_chamber
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  9. #8  
    WYSIWYG Moderator marnixR's Avatar
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    let's not confuse the tanks with (heavy ?) water used to detect neutrinos with cloud chambers : they're totally different things

    a cloud chamber is filled with supercooled + supersaturated water vapour which as a result of any disturbance become water droplets and leave a visible trail, a bit like a plane in the sky
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  10. #9  
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    Quote Originally Posted by marnixR
    as far as i'm aware none of the particle accelerator experiments have managed to produce a naked quark
    what did happen though is that entities were observed that were best explained as consisting of 2 quarks, whereas protons and neutrons are made up of 3
    So were these two quarks derived from protons or neutrons, or was it from some process entirely unrelated to protons and neutrons?
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  11. #10  
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    http://www.fnal.gov/pub/presspass/pr...ingle-Top.html

    Tentative evidence for the production on a single quark from the collision of protons and antiprotons.
    Disclaimer: I do not declare myself to be an expert on ANY subject. If I state something as fact that is obviously wrong, please don't hesitate to correct me. I welcome such corrections in an attempt to be as truthful and accurate as possible.

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  12. #11  
    Moderator Moderator AlexP's Avatar
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    What I picked up from the wikipedia article on hadronization is that free quarks are created but the always hadronize very quickly, so we never actually detect them as free quarks. Also, it's worth noting that the top quark has been detected as a 'bare' quark because it decays so quickly that the strong force can't hadronize it before it does so.
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