Virtual Particles and Charge Screening

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SUMMARY

The discussion centers on the concept of virtual particles and their role in charge screening, specifically in the context of quantum fluctuations. It asserts that while some argue virtual particles are merely bookkeeping devices, they are essential for explaining phenomena like the running of electromagnetic coupling and charge measurement variations. The charge of an electron is observed to be less than its bare charge due to the influence of surrounding electron-positron pairs, which can be analyzed through photon self-energy calculations. Understanding these concepts requires familiarity with advanced topics such as the beta function and renormalization group equations.

PREREQUISITES
  • Quantum field theory fundamentals
  • Feynman diagrams and perturbation theory
  • Photon self-energy calculations
  • Renormalization group equations
NEXT STEPS
  • Study the beta function in quantum field theory
  • Explore the implications of renormalization group equations
  • Learn about the role of quantum fluctuations in particle physics
  • Investigate the mathematical framework of Feynman diagrams
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Physicists, advanced students of quantum mechanics, and researchers interested in particle physics and quantum field theory.

David Neves
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The following article says virtual particles don't exist or are just book keeping device.

https://www.physicsforums.com/insights/physics-virtual-particles

If that's the case, then how do you explain charge screening? We observe the charge of an electron to be less than the bare charge, or what it really is, because it is surrounded by a cloud of electron-positron pairs. Experiments confirm that the measured value of the electron's charge is determined by the distance fro which you measure it. How do you explain that without virtual particles?
 
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The "charge screening" or more accurately running of the electromagnetic coupling is due to quantum fluctuations. It can be calculated most simply by evaluating the photon self-energy. Of course, here "virtual particles" occur as explained in the Insights article, namely as internal line of Feynman diagrams, where they stand for propagators of the fields and thus well-defined mathematical expressions of perturbation theory.
 
You still need bookkeeping.

There probably is no answer at the intermediate level - to see what is going on involves the beta function in particular and the renormalization group equations in general, neither of which are undergraduate concepts.
 

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