Can the separation of quarks create new baryon matter?

  1. I read recently, that by separating two quarks, once a high enough energy has been introduced, new quark pairs will form. This sounds to me like a meson, being turned into two mesons. I don't know how clear I am on this, but I was wondering... Is the same true for Baryons. If we magically pull out quarks from protons, neutrons, Is new baryonic matter created somehow?? I am specifically wondering if the separation of quarks could possibly create new hydrogen, therefore introducing new stable matter into the universe as a direct result of energy input. I realize this is highly unlikely, but I am wondering if conservation of baryon number, or something else, forbids this. Thanks!!
  2. jcsd
  3. mfb

    Staff: Mentor

    Yes, new baryons and antibaryons are created in that way. They are produced in exactly the same amount and the antibaryons annihilate with baryons (unless you send them to space - did not happen yet, and there is no reason to do so) afterwards, so the total number of baryons does not change.
  4. Interesting... So, creating hydrogen in a lab, is not really feasible is it? It sounds like matter always annihilates in the end. Are there any cases where scientists believe it is possible to create matter from pure energy?
  5. Drakkith

    Staff: Mentor

    We can and already do in particle colliders. That's how we get antimatter and trap it. (We could just as easily trap the normal matter, but we don't care about that since its everywhere) Note that baryons are numbered +1 for normal baryons, -1 for antibaryons, and 0 for mesons. The conservation law states that the baryon numbers will add up to zero, not that the total number of particles and antiparticles must equal the original number in the interaction. If it did, we wouldn't get jets of particles from particle collisions.
  6. baryons are made out of 3 quarks, aren't they? So I see no reason why it would create new bariyons, but I'm not sure
  7. I see, therefore... It's not physically possible to increase baryon number by 1 (truly adding to the existing matter in the world, without annihilations). I think I got it.
  8. Bill_K

    Bill_K 4,157
    Science Advisor

    I hope you understand that what you're describing is impossible -- quarks cannot be "separated"! If a quark is driven away from the other quarks in a proton, by a high-energy collision for example, it will snap right back.

    What actually happens is that when a quark undergoes a violent acceleration like this, it radiates. That is, it produces the QCD analog of bremsstrahlung radiation, namely a shower of gluons. The gluons then decay into quark-antiquark pairs.
  9. That is interesting. So there is literally no way of separating the three quarks? You can't even change the quark it is attathed to?
  10. I don't know that this is really a fair thing to say. If you kick an up quark hard enough out of a proton, it may not be an up quark that gets "sucked back" into the hadron. It could be any sort of quark. A picture in which the up quark "really escapes" the proton seems appropriate to me. Sure, fragmentation and hadronization is a complicated process, but the use of language implying that the initial hadron can be "broken apart" is pretty common, and seems perfectly justified to me.
    Last edited: Nov 21, 2013
  11. Bill_K

    Bill_K 4,157
    Science Advisor

    It's a common mistake.
  12. Would you mind explaining further what is wrong with such a picture? For example, if we consider p p --> p Ʃ+ K0, in what sense is it wrong to say that the valence d quark from one of the protons was kicked out, paired with an sbar to form the K0, while the corresponding s quark stayed with the remnants of the proton to form the Ʃ+? I know it is a simplified description of a whole mess of strong dynamics, but I don't fully grasp your objection. I mean the quantum numbers of the Ʃ+ and p are clearly different, so I don't see why you think it is better to say that none of the quarks ever leave the initial hadron.
  13. mfb

    Staff: Mentor

    Diagrams like this are common QCD decay modes and I think they match the description of Herbascious J.


    And the hadronization after hadron collisions has those processes everywhere.

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