I read Feynman's book but this still unclear to me.
Asked
Active
Viewed 187 times
0
-
What aspect of the electron? – garyp Dec 25 '19 at 15:40
-
It's radius. In classical physics the electron has a finite radius. In QED it has none. – Larry Dec 25 '19 at 16:28
1 Answers
0
Present day particle physics is encapsulated in the standard model of particle physics, after more than fifty years of experimentally studying elementary particles. All the particles in the axiomatic table of the standard model are point particles, some have mass, but all have zero volume, they are assumed to be point particles.
The model is a field theoretical model, not only QED, which is just the electromagnetic interaction. The QFT calculations validate the model, i.e can describe the great majority of data, and are successful in predictions. That is why the field theories used for strong, weak, and electromagnetic interactions assign zero volume for the standard model particles, of which the electron is one.
Experiments putting limits on the size of the electron are done; at at this moment, within experimental errors, assuming zero volume for the particles in the table is consistent with data.
If at some future data new experiments nail a dimension for the electron or another particle, the standard model theory will have to be revised.
See also the question and answer here Experimental boundaries for size of electron?
anna v
- 233,453