Witten-Veneziano Relation, Quenched QCD, and Overlap Fermions

TL;DR

This paper investigates the relationship between topological susceptibility and eta-prime mass in quenched QCD using overlap fermions, confirming the Witten-Veneziano relation as exact in this framework.

Contribution

It demonstrates that the Witten-Veneziano relation is exact with overlap fermions and computes key parameters like the eta-prime mass in quenched QCD.

Findings

Confirmed the Witten-Veneziano relation as exact with overlap fermions

Computed the eta-prime mass and topological susceptibility in quenched QCD

Analyzed the low energy chiral properties using fermionic zero modes

Abstract

The quarks in quenched QCD have an anomalous self-interaction in the flavor singlet Goldstone boson channel. This coupling is extracted from a graph with disconnected quark lines, and is used to infer the mass of the eta-prime meson in full QCD. When the fermions are described by an overlap action, the Witten-Veneziano relation is an exact relation between the topological susceptibility (as defined through fermionic zero modes) and the inferred value of the eta-prime mass. Using an overlap action we compute the hairpin amplitude and determine the fermion zero-mode susceptibility, the inferred eta-prime mass and other parameters characterizing the low energy chiral properties of quenched QCD.