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Proton, antiproton annihilation

  1. Mar 13, 2012 #1
    Need help with this question.

    What are the wavelengths of the two photons produced when a proton and antiproton at rest annihilate?

    Any help is appreciated, thank you :)
  2. jcsd
  3. Mar 13, 2012 #2

    Use energy conservation and the de broglie relation between energy and wavelength.
  4. Mar 13, 2012 #3


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    Gold Member

    Also note that even for slow proton/antiproton, the energy available allows for many reaction products. Mixtures of pions and gammas are common. Even e+e- is a possible product. The only reason for the myth that annihilation produces photons is that for slow e+/e- there is almost no other available path (there actually is one exceedingly rare alternative even for slow electron positron: a neutrino - anti-neurtrino pair; doubt this has ever been verified experimentally).
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