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Quantum field theory

  1. Mar 29, 2004 #1
    If a photon was made from more than one particle, how would quantum field theory be modified?
     
  2. jcsd
  3. Mar 29, 2004 #2

    selfAdjoint

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    A spin 1 field, like the photon's, can be represented as the combination of two spin 1/2 fields. This is an idea that IIRC goes back to Schwinger. It's just math, because the spin 1/2 fields are not observed, and don't have any collective effects that are observed either. Note the difference from quarks, which are not observed but whose collective effects can be calculated and matched to experimental results.

    Various people have put forward theories with these unobservable fermions generating the photons, but I have yet to see one that is well enough constructed in detail for other physicists to take it seriously.

    Contrary to what you often hear, physics is not averse to wild and crazy ideas per se. But it does require that creators do their homework and link their theories to observation. All the fantastic level of detail observation that 100 years of experiment have given us, and which ordinary quantum mechanics does link to successfully. Just shouting over and over that my theory is important and the wicked old scientists are suppressing it won't work.
     
  4. Mar 29, 2004 #3
    a photon is represented as two fermions? what the... can you provide a reference for this? every treatment of QED i have ever seen treated the photon field as a vector potential, satisfying commutation relations (not anticommutation). I have never seen this done, but I have read that some people have also tried quantizing the field strength itself, instead of the vector potential, but either way, it is still a bosonic field.

    i am not saying you are wrong, nor trying to get into an argument with you, but i am just saying that I have never heard of what you are saying, and would like you to back it up with some references.

    selfAdjoint: please provide a reference that shows the photon field being represented as two fermionic fields!
     
  5. Mar 29, 2004 #4

    Tom Mattson

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    I've never read any theory that treats the photon as two fermions, but does not sound all that far fetched. Consider a BEC formed by rubidium atoms for an example of a collection of fermion fields that obeys Bose-Einstein statistics.
     
  6. Mar 29, 2004 #5

    Tom Mattson

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    SelfAdjoint:

    In these theories in which the photon is treated as two fermions, how is the MS=0 state suppressed, so that the eigenvalues of Jz are restricted to ±1? A would-be theorist (p_mintz) posted his idea for treating the photon as 2 fermions over a year ago and I asked him the same question, but he had no answer for me. :frown:

    edit: fixed a typo
     
  7. Mar 29, 2004 #6

    selfAdjoint

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    Tom, I haven't a clue. I haven't studied any of these theories deeply.
     
  8. Mar 29, 2004 #7
    selfAdjoint: can you provide a reference, a source, a name, for a theory that treats the photon as two fermions?
     
  9. Mar 29, 2004 #8

    selfAdjoint

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    Well the one I can't stand is from our occasional poster dr Ameen. And Tom just mentioned another one. Hey, I never said they were reasonable!
     
  10. Mar 29, 2004 #9
    were you refering to crackpot theories?
     
  11. Mar 30, 2004 #10
    How is the M spin = 0 state suppressed?
    A good point.I'll let you know when my theory can explain it!
    This is the crux of the matter.
     
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