On the renormalization of the bosonized multi-flavor Schwinger model

TL;DR

This paper studies the phase structure of the multi-flavor Schwinger model using renormalization group techniques, revealing different symmetry behaviors depending on the number of flavors and fermion mass regimes.

Contribution

It applies differential RG methods to analyze the bosonized multi-flavor Schwinger model, providing new insights into its low-energy behavior and symmetry breaking patterns.

Findings

For N>1, reflection symmetry breaks down in all regimes.

For N=1, reflection symmetry remains unbroken in the strong coupling phase.

Low-energy behavior varies significantly between N=1 and N>1 cases.

Abstract

The phase structure of the bosonized multi-flavor Schwinger model is investigated by means of the differential renormalization group (RG) method. In the limit of small fermion mass the linearized RG flow is sufficient to determine the low-energy behavior of the N-flavor model, if it has been rotated by a suitable rotation in the internal space. For large fermion mass, the exact RG flow has been solved numerically. The low-energy behavior of the multi-flavor model is rather different depending on whether N=1 or N>1, where N is the number of flavors. For N>1 the reflection symmetry always suffers breakdown in both the weak and strong coupling regimes, in contrary to the N=1 case, where it remains unbroken in the strong coupling phase.