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Thread: quark conversion

  1. #1 quark conversion 
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    When a neutron decays into a proton, a down quark emits a W<sup>-</sup> boson, which decays into an electron and an electron antineutrino. What I don't understand, is where the W<sup>-</sup> boson comes from, because the down quark is an elementary particle, so it is not made of a W<sup>-</sup> and an up quark, obviously. And anyway, the W<sup>-</sup> is much much heavier than the down quark, so it couldn't be there originally, or the down quark would be much heavier... So where's it come from?


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    As far as I know the W~ particle immediately decays into an electron and an anti-neutrino. And this all happend in a billionth of a billionth of a billionth of a second.


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  4. #3  
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    Quote Originally Posted by leohopkins
    As far as I know the W~ particle immediately decays into an electron and an anti-neutrino. And this all happend in a billionth of a billionth of a billionth of a second.
    yes...I know. What I'm asking is where the W<sup>-</sup> comes from in the first place.
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    This is one of the reasons why I personally believe that the neutrino has anti-mass and so the laws of mass are conserved. However, I have to say that I really don't know. Maybe someone more learned than I would care to explain?
    8)
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  6. #5 Neutron Decay 
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    I have it worked out that the neutron decay does not involve quarks emiting other particles.

    I worked it out as a quark swopping procedure:

    dud + ~uu --> udu + ~ud (1)

    ~u = anti-up quark. Where the ~ud decays into an electron and electron-antineutrino and the ~uu is created from energy.

    This has applications in Supernovae: protons decaying in the inverse way as (1) and releasing energy from ~uu annihilation.
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  7. #6 quark conversion 
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    :-D

    There is another logical objection to quark conversion:

    for the process:

    d -> u and d releases W - minus

    the in between state of the process is undefined, and if you define it as a superposition of the three particles then the exclusion principle gets violated.

    The quark swopping process above does not suffer from this problem: the in between state is simply gluons detatching and reattaching to the swopped quarks.
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    From what I have read, the energy for the w-boson is borrowed, and then emitted.
    As I read in one of my books "if you are in a two ton car, and ten tons was suddenly emitted, you would think something was wrong! But in particle physics, this is all possible".
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  9. #8  
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    :?

    That does not define the in between state.
    It also matters what isn't there - Tao Te Ching interpreted.
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  10. #9  
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    What I've read since I posted this thread is that the W boson is a virtual particle, and it exists for such a short amount of time that it doesn't count as violating the laws of conservation of mass and energy.
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  11. #10  
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    :x

    What about the u quark: does it come from the d or from the W boson? What influence from the d is going to make a u at a distance form the d?
    What about the exclusion principle applied to the d and u.

    You are stating that the in between state is a virtual W and a d in the process of transforming it's charge into that of a u (while the W is also getting charge).

    What about the strong force and the W: won't it be attracted to the ddu/duu?

    I think this violates a stronger form of charge conservation (structure conservation), wether the W is virtual or not.
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  12. #11  
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    Quote Originally Posted by talanum1
    :x

    What about the u quark: does it come from the d or from the W boson? What influence from the d is going to make a u at a distance form the d?
    What about the exclusion principle applied to the d and u.

    You are stating that the in between state is a virtual W and a d in the process of transforming it's charge into that of a u (while the W is also getting charge).

    What about the strong force and the W: won't it be attracted to the ddu/duu?

    I think this violates a stronger form of charge conservation (structure conservation), wether the W is virtual or not.
    The u quark comes from the d quark by emission of the W<sup>-</sup> boson, as a result of weak decay.

    The Pauli exclusion principle isn't violated here because the quarks will have different quantum numbers, and the d quark ceases to exists after the conversion anyway, so it doesn't remain to share any quantum numbers with the u quark.

    W bosons do not feel the strong force, and they do feel the electromagnetic force, so they might be attracted to the new proton, but my guess is that they decay before the EM force has a chance to interact with them.

    As for charge, it is conserved, because the d quark has a charge of -1/3, while the u quark has a charge of +2/3. The W boson emitted has a charge of -1, and thus charge is conserved because it is carrying away the negative charge to produce a charge in the new quark that is exactly 1 higher than in the d quark. Charge is also conserved after the W<sup>-</sup> decays because it decays into an electron with a charge of -1 and an electron antineutrino (neutral).
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  13. #12 quark conversion 
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    :?

    EMITS a W? Then the d quark has both primitive and compound structure before it emitted it.
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  14. #13  
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    :?

    I mean: you would have to define the W being inside/around/attached to the d. In wich case the d quark would have both color neutral and color red/green/blue as well as both charge -1 and charge -1/3, and similarly for spin and isospin if they are not the same.
    It also matters what isn't there - Tao Te Ching interpreted.
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