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Matter-Antimatter Pairs

  1. Jan 13, 2010 #1
    Why does an matter-antimatter pair annihilate each other instead of "sticking" together (i.e. like ordinary matter with opposite charges do)?
  2. jcsd
  3. Jan 13, 2010 #2

    Physics Monkey

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    In fact, they don't always annihilate right away. For example, an electron and a positron may form a bound state called positronium. Positronium doesn't live forever, but a certain form of it can live for a relatively long amount of time, more than 100 nanoseconds! That may not sound like much, but it does show that matter and anti matter don't have to immediately annihilate.


    Hope this helps.
    Last edited by a moderator: Apr 24, 2017
  4. Jan 13, 2010 #3
    A relativistic positron can annihilate in flight with an atomic electron in matter. The integrated probability for a 50-MeV stopping positron is ~ 15%. See pages 384-6 in Heitler "The Quantum Theory of Radiation" Fourth Edition.
    Bob S
  5. Feb 14, 2010 #4
    Thank you very much for the feedbacks! I appreciate it. =)
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