Massive Schwinger model at finite $\theta$

TL;DR

This paper investigates the massive 1-flavor Schwinger model with a theta term, reconstructing its behavior and confirming Coleman's conjecture on its phase diagram at theta equals pi.

Contribution

It applies a specific reconstruction approach to analyze the model's order parameter dependence on theta, providing new insights into its phase structure.

Findings

Order parameter dependence on theta reconstructed

Results at theta = pi support Coleman's conjecture

Behavior of the model consistent with theoretical predictions

Abstract

Using the approach developed in [V. Azcoiti, G. Di Carlo, A. Galante, V. Laliena, \textit{Phys. Lett.} \textbf{B563}, (2003) 117], we are able to reconstruct the behavior of the massive 1-flavor Schwinger model with a $\theta$ term and a quantized topological charge. We calculate the full dependence of the order parameter with $\theta$. Our results at $\theta = \pi$ are compatible with Coleman's conjecture on the phase diagram of this model.