Why Do Matter-Antimatter Pairs Annihilate Instead of Sticking Together?

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SUMMARY

The discussion centers on the behavior of matter-antimatter pairs, specifically why they annihilate instead of forming stable structures. It is established that while matter-antimatter pairs, such as electrons and positrons, typically annihilate, they can form a bound state known as positronium, which can exist for over 100 nanoseconds. This indicates that annihilation is not immediate and depends on specific conditions. Additionally, the probability of a relativistic positron annihilating with an atomic electron is approximately 15% for a 50-MeV stopping positron, as detailed in Heitler's "The Quantum Theory of Radiation".

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  • Understanding of quantum mechanics principles
  • Familiarity with particle physics terminology
  • Knowledge of positronium and its properties
  • Basic grasp of relativistic effects in particle interactions
NEXT STEPS
  • Research the properties and behavior of positronium in detail
  • Study the implications of relativistic effects on particle interactions
  • Explore the integrated probability calculations for particle annihilation
  • Examine Heitler's "The Quantum Theory of Radiation" for deeper insights
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Physicists, students of particle physics, and anyone interested in the interactions between matter and antimatter will benefit from this discussion.

quantumkiko
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Why does an matter-antimatter pair annihilate each other instead of "sticking" together (i.e. like ordinary matter with opposite charges do)?
 
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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.
 
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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
 
Thank you very much for the feedbacks! I appreciate it. =)
 

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