Positrons
The positron is an example of a particle with similar mass to an electron (~511KeV), but displaying "positive" rather than "negative" behaviour in response to an electric field.
The observed difference in "charge" behaviour is expected to be due to a different electromagnetic field configuration compared to the electron. For example the positron field may be more "toroidal compared to the electron field which is expected to be more spherical.
The existance of electrons rather than positrons under normal conditions is consistent with the electron magnetic field configuration being stable, whereas the positron field configuration is unstable.
The positron size has not been described (?), but it could perhaps be close to the size expected for a particle of this mass in accordance with "wave-particle equivalence", i.e. ~1,840x larger than nucleons?
Copyright S. Brink.
Positron - A 511KeV particle in a
toroidal orbit?
