On the isotopic spin of elementary particles

Abstract

It is shown that the electron, the positron and the Majorana neutrino can be described jointly as three charge states of a single particle, the lepton, which in contrast to the nucleon is an elementary particle with isotopic spin 1. Similarly, the mesons π^± and π⁰ are described jointly as three charge states of a single particle, the pion, with isotopic spin 1. Interactions of the lepton field (and also of the pion field) with the electromagnetic field and with the nucleon field are considered. The whole theory is shown to be independent of any special choice of the representation of the isotopic spin operators.