Topology and pion correlators -- a study in the N_f=2 Schwinger model

TL;DR

This study investigates how the topological charge of the gauge background affects pion correlators in the N_f=2 Schwinger model, revealing a dependence related to sea-quark mass and volume similar to QCD.

Contribution

It provides a detailed analysis of topological charge effects on hadronic observables in the Schwinger model with dynamical fermions, highlighting a specific dependence analogous to QCD.

Findings

Pion correlators vary with fixed topological charge.

Dependence on sea-quark mass and volume is analogous to Leutwyler-Smilga parameter.

Topological charge influences hadronic observables in the model.

Abstract

I readdress the issue whether the topological charge of the gauge background has an influence on a hadronic observable. To this end pion correlators in the Schwinger model with 2 dynamical flavours are determined on subensembles with a fixed topological charge. It turns out that the answer depends on a specific function of the sea-quark mass and the box volume which is in close analogy to the Leutwyler-Smilga parameter in full QCD.