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Is it possible for a photon lifetime to be complex ?

  1. Sep 11, 2012 #1

    In my calculation of photon lifetime, results are coming as complex number. So being a new one in this field I am just confused whether a photon lifetime ca be complex or somewhere I am making some mistake.
  2. jcsd
  3. Sep 11, 2012 #2


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    Science Advisor

    No, it is not possibe. "time" is a real valued quantity.

    (This also is not "academic guidance")
  4. Sep 11, 2012 #3


    Staff: Mentor

    If you post the calculation we can probably help find the error.

    It is also possible that the number is zero, with simple numerical precision issues giving the complex part.
  5. Sep 11, 2012 #4


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    I'm wondering how it is possible for a photon to decay at all! What does it decay to?
  6. Sep 11, 2012 #5
    What do you mean when you say decay?

    The "life" of a photon typically refers to the expectation value of the time it takes for a photon to be attenuated by the medium through which it is passing. Attenuation occurs due to physical interactions between the photon and the medium (photoelectric effect, Compton scattering, pair production, photodisintegration, etc.).
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