Abnormal solutions of Bethe--Salpeter equation with massless and massive exchanges
Abnormal solutions of Bethe--Salpeter equation with massless and massive exchanges
We summarize the main properties of the so called ''abnormal solutions'' of the Wick--Cutkosky model, i.e. two massive scalar particles interacting via massless scalar exchange ("photons"), within the Bethe--Salpeter equation. These solutions do not exist in the non-relativistic limit, in spite of having very small binding energies. They present a …