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Could very low energy virtual particles last a very long time?

  1. Apr 10, 2012 #1
    By looking at layman's books on physics I have picked up the idea that "virtual" particle-antiparticle pairs continually pop out of the vacuum and then back into it again.

    Apparently according to the Heisenberg Uncertainty Principle the time that the particle pair can exist, [itex]\Delta t[/itex], is given by

    [itex] \Delta t \approx h / \Delta E [/itex]

    where [itex] \Delta E [/itex] is the energy of the particle pair.

    Is there any lower limit to [itex]\Delta E[/itex] like the neutrino mass? Or could the particle pair be a pair of photons with any energy?

    Could [itex]\Delta t[/itex] be billions of years if the particle-pair has a very very low energy ?
    Last edited: Apr 10, 2012
  2. jcsd
  3. Apr 10, 2012 #2


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    [itex]\Delta E[/itex] can be interpreted as the deviation from a proper particle energy&momentum. Particles which are very close to the properties of "real" particles can last a very long time. For pairs of particle+antiparticle with a rest mass, this quantity has to be quite large, which makes these pairs short-living.
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