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Quark decay and particle materialization

  1. Sep 25, 2011 #1
    Hello!

    I have read that in the case of beta decay, a neutron becomes a proton

    neutron = proton + electron + antineutrino

    but the electron and antineutrino are ''materialized'' by the emission of an intermediate w- boson. What does ''materialize'' mean in this context? I have thought of the w boson inputting the necessary energy to collapse the electron's and antineutrino's wafe function in some place where their probabilities are nonzero.

    Can anyone help me understand the meaning of 'materialize' in this context ?
     
  2. jcsd
  3. Sep 26, 2011 #2

    Drakkith

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    Staff: Mentor

    Sounds like they just mean that it is created. How could the wavefunctions collapse if the particles didn't exist before that?
     
  4. Sep 26, 2011 #3
    How are they created?
     
  5. Sep 28, 2011 #4
    Would anyone mind shedding some light on this problem?
    How can a boson create a particle-antiparticle pair without breaking the energy conservation law?
     
  6. Sep 28, 2011 #5

    Drakkith

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    Staff: Mentor

    What about it breaks the conservation law? The energy is removed from a down quark as it is converted to an up quark which is lighter in mass.
     
  7. Sep 28, 2011 #6
    Ok thank you.

    But, now, wouldn't it imply that electrons and antineutrinos are some of the constituents of the W boson, and by extension, of the neutron?
     
  8. Sep 28, 2011 #7

    Drakkith

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    Staff: Mentor

    Nope. They are created by the mass/energy of the particle when it decays. Note that in particle colliders it is routine to collide two or more particles together and get a shower of newly created particles that have a rest mass GREATER than the rest mass of the original colliding particles. This does not imply that the original particles were made up of all these other particles, but that the energy of the original particles is converted into mass for creation.

    See here for more: http://en.wikipedia.org/wiki/Elementary_particle

    Edit: Forgot to mention the fact that W-Bosons can also decay into quark-antiquark pairs. In this case and in the beta decay case, the energy and mass is completly accounted for. If both quark-antiquarks AND electrons and neutrions were created at the same time that would be a violation, as there isn't enough energy. So clearly a W-Boson cannot be composed of any of these particles as we should see them in every decay, which we don't.
     
    Last edited: Sep 28, 2011
  9. Sep 28, 2011 #8
    Thank you, I appreciate !
     
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