Undergrad Virtual Particles and Charge Screening

[David Neves]

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?

 

[vanhees71]

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.

 

[Vanadium 50]

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.