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I Conservation and W boson

  1. May 14, 2018 #1
    Is this true?:
    During beta decay a quarks' spin is changed and the mass/ energy difference is converted to a W boson which quickly decays into an electron/positron and an anti neutrino/neutrino. The mass/ energy is conserved through E=mc^2.
  2. jcsd
  3. May 14, 2018 #2


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    You really cannot say that the W exists in any meaningful manner. The energies involved in beta decay are far below that necessary to create a real W boson. However, the dominant contribution to beta decay is the exchange of a virtual W boson.
  4. May 14, 2018 #3
    Thanks for your reply, would the other parts of my explanation be correct?
  5. May 14, 2018 #4


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    The type of quark is changed, not its spin.

    The isospin changes (which is a fancy name for saying the type changes).
  6. May 15, 2018 #5
    Awesome, thank you for your reply mfb!
  7. May 17, 2018 #6


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    I think the spin can also change, but it's not a rule (as there are W bosons with spin component 0 and with spin component +/-1)... the +/-1 should flip the spin of the quark, the 0 should keep it as it is. The spin quantum number though remains the same, for example both d and u-quarks have spin=1/2 (as all quarks and known fundamental fermions) , with components +/-1/2 each. Of course most of the times the spin-components are averaged out in calculations.
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