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Photon's role

  1. Feb 26, 2005 #1
    Photon doesn't interact with external force and move with light speed. But why can it act as force carrier, play a role in photoelectric etc.?
     
  2. jcsd
  3. Feb 26, 2005 #2
    I think your question rise from the misunderstanding the concept of foton!!! and try to understand it with classical means.
    when you quantize the electromagnetic field, you see a harmonic ossilator in somewhere. and they call it foton.
     
  4. Feb 26, 2005 #3

    dextercioby

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    We address gauge fields to be carriers of "force".All 4 fundamental interactions are mediated by gauge fields...Photon is the quanta of the EM field,which is a gauge field and can mediate the EM interaction.

    As for "external force",i don't see what you could possibly refer to.

    As for "harmonic oscillators",the analogy is not good,not good at all...

    Daniel.
     
  5. Feb 26, 2005 #4

    jtbell

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    What, precisely, are you thinking about in connection with this statement? Photons most certainly do interact with charged particles via the electromagnetic interaction at its fundamental level.
     
  6. Feb 26, 2005 #5

    dextercioby

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    Come again...?Photons interact with photons (in QED,not EW,or SM) via lepton-antilepton pairs,and viceversa...PHOTONS ARE ELECTROMAGNETIC INTERACTION...

    Daniel.
     
  7. Feb 26, 2005 #6

    This is wrong. Photons do NOT mutually interact unlike the gluons from QCD for example. The emitted photons coming from matter-amtimatter interactions do NOT mutually interact


    marlon
     
  8. Feb 26, 2005 #7

    dextercioby

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    What...??Photons do interact,check QED again...Especially the last section from Ahizer & Berestetzkii,where the diff.cross-section for photon-photon scattering is computed...

    Daniel.
     
  9. Feb 26, 2005 #8
    :surprised What is the gauge boson that mediates the foton-foton-interaction ?

    Remember, this is a raethorical question, so don't try to give a right valid answer because there ain't no such gauge boson.

    marlon
     
  10. Feb 26, 2005 #9

    dextercioby

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    It's not a gauge-boson,there are 2 pairs of massive lepton-massive antilepton...Take the book,Marlon...:rolleyes:

    Take the pencil.Compute the S-Matrix for QED in the 4-th order and then the amplitude of probability of transition between the initial state with 2 photons and final state with 2 photons...That is the simplest example of photon-photon scattering...

    You claim to know so much,yet u sometimes cannot prove it...

    Daniel.

    P.S.Don't argue for the sake of arguing,especially when u're wrong...
     
  11. Feb 26, 2005 #10
    Sorry, this is just balony. I happened to have that book and you clearly are misinterpreting this content. What you write does NOT prove that photons interact. You are wrong on this specific argument for the above reason.

    Please, let us not get personal and please do try to stay more polite and mature in your answers.

    I am not wrong, my dear friend. Don't deny the abelian field theory. Photons do not Interact, PERIOD.

    marlon
     
  12. Feb 26, 2005 #11

    dextercioby

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    Nope.Electrons are scattered one on another (Mo/ller scattering),just the same way photons are scattered one on another...Electrons need a photon,photons,need 2 electrons and 2 positrons.

    What is the specific chapter called...?

    Daniel.
     
  13. Feb 26, 2005 #12

    selfAdjoint

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    Please, both of you. Somebody quote the relevant text from Ahizer & Berestetzkii and interpret it and discuss THAT. Get off this did-so, did-not third grade argument!
     
  14. Feb 26, 2005 #13
    Look,

    From Quantum Electro Dynamics (QED) we know that Photons cannot couple directly to each other, since they don't carry charge, but they can interact through higher order processes:
    A photon can, within the bounds of the uncertainty principle, fluctuate into a charged fermion/ anti-fermion pair, to either of which the other photon can couple. This fermion pair can be leptons or quarks.


    It is misleading to say that photons interact because people will copare this to two charged particles interacting...This is a totally differe,t type of (indirect) interaction


    marlon
     
  15. Feb 26, 2005 #14
  16. Feb 27, 2005 #15

    dextercioby

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    I'm glad we finally reached an agreement.

    Daniel.
     
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