Against the point-like nature of the electron

Abstract

Experts in quantum field theory (QFT) generally answer the question of the ``size of an electron'' with ``point-like''. On the other hand, QFT recognizes quantum effects, shielding by virtual particles, the so-called polarization cloud, which should describe the size of physical electrons. Scattering experiments with electrons, such as those carried out in high-energy experiments at particle accelerators, should be able to clarify whether physical electrons are really point-like, as claimed by experts and in textbooks. In this article, I show that both the formulas of QFT and the corresponding cross sections are consistent with an extent of the electron of the size of the classical electron radius. The assumption that the relativistic energy of electrons in the high-energy limit consists solely of deformation energy from the extended electron density distribution allows for a simple interpretation of the experimental cross sections. For this reason, I refer to classical models in 1+1 and 3+1 dimensions that have precisely this property. The difference between the terms point-like, structureless, and substructureless is highlighted. The usual objections to the claim that the electron radius is finite and has already been measured in electron scattering experiments are discussed.