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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.

    http://prl.aps.org/abstract/PRL/v90/i20/e203402
    http://physicsworld.com/cws/article/news/17559
    http://en.wikipedia.org/wiki/Positronium

    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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