arXiv subjects
Publications and source records attributed to Christoph Adam.
We use (fermion) mass perturbation theory for the massive Schwinger model to compute the boson-boson bound state mass in lowest order. For small fermion mass the lowest possible Fock state turns out to give the main contribution and leads to a second order result for the bound state mass.
For the exactly solvable Schwinger model one interesting question is how to infer the exact solution from perturbation theory. We give a systematic procedure of deriving the exact solution from Feynman diagrams of arbitrary order for arbitrary $n$-point functions. As a byproduct, from perturbation theory we derive exact integral equations that the $n$-point functions have to obey.