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Homework Help: Quantum mechanics

  1. Dec 8, 2005 #1
    Charges of +q and -q are separated by a distance L.

    What would be a typical energy of a virtual photon they exchange?
     
  2. jcsd
  3. Dec 9, 2005 #2
    what have you done so far?

    why would they exchange a virtual photon in the first place?
     
  4. Dec 9, 2005 #3

    dextercioby

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    Why do you mix photons with "distance L" ...?

    Daniel.
     
  5. Dec 9, 2005 #4

    I stated the problem as it is given in the book
     
  6. Dec 9, 2005 #5

    dextercioby

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    Well, virtual photons are terms used in QED, but "distance L" between 2 pointlike charges has to do with classical electrodynamics, i.e. electrostatics...Do you see anything suspicious...?

    Daniel.
     
  7. Dec 9, 2005 #6
    draw the feynman diagram. do conservation of momentum.
    treat it like a collision.
     
  8. Dec 9, 2005 #7
  9. Dec 9, 2005 #8
    Can you not just use the time version of the uncertainty principal to determine the energy of the virtual photon? You can express [tex]\Delta t[/tex] in terms of L and c and find [tex]\Delta E[/tex].
     
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