Probing Instanton Dynamics in the Pion Vector Form Factor with Wilson Flow

TL;DR

This paper investigates the instanton liquid model's predictions for the pion electromagnetic form factor using Wilson flow to isolate instanton effects in lattice QCD simulations, providing preliminary insights into non-perturbative QCD dynamics.

Contribution

It introduces a novel approach to study the pion form factor by applying Wilson flow to lattice QCD data, focusing on instanton contributions and comparing with existing model predictions.

Findings

Preliminary results show the effectiveness of Wilson flow in isolating instanton effects.

Initial data suggests agreement with instanton liquid model predictions.

Methodology sets the stage for more precise non-perturbative QCD studies.

Abstract

Instanton liquid model is believed to capture the main features of vacuum QCD dynamics. Recently, multiple predictions for hadron structure functions have been derived and compared with experimental measurements and lattice QCD calculations, finding a general agreement. In order to explore the precision of the instanton liquid model, one has to compare its predictions with non-perturbative simulations in a regime dominated by instanton dynamics. This has been performed for two gluon-sensitive observables: the gluon Green's function and the strong running coupling constant. In this contribution, we propose to study a fermionic observable, the pion electromagnetic form factor, for which instanton liquid model predictions have been discussed in Phys.Rev.D 109, 074029. We use the Wilson flow to single out the dominant contribution from the instantons out of a lattice QCD configuration ensemble. We describe the details of our numerical setup, and some first, preliminary results.