Speaker
Description
We study the massless Schwinger model with an additional 4-fermi interaction and a topological term. For topological angle $\theta = \pi$ charge conjugation is implemented in a non-trivial way and we study its spontaneous breaking. We use staggered fermions and the Villain action for the gauge fields, where the topological term is an integer and charge conjugation at $\theta = \pi$ is an exact symmetry. The complex action problem is overcome by a suitable worldline/worldsheet representation. We find that as a function of the 4-fermi coupling the system has a critical point where charge conjugation is broken spontaneously and we present first results on the nature of the critical point.