Suppression of excited-state effects in lattice determination of nucleon electromagnetic form factors

TL;DR

This paper evaluates various fitting techniques to accurately extract nucleon electromagnetic form factors from lattice QCD data, emphasizing the importance of excited-state suppression and physical pion mass proximity.

Contribution

It introduces an analysis of excited-state contamination treatment methods in lattice calculations, demonstrating their impact on form factor determination at near-physical pion masses.

Findings

Effective suppression of excited-state effects improves form factor accuracy

Approaching physical pion mass significantly influences form factor $Q^2$-dependence

Fitting techniques are crucial for reliable lattice nucleon structure results

Abstract

We study the ability of a variety of fitting techniques to extract the ground state matrix elements of the vector current from ratios of nucleon three- and two-point functions that contain contaminations from excited states. Extending our high-statistics study of nucleon form factors, we are able to demonstrate that the treatment of excited-state contributions in conjunction with approaching the physical pion mass has a significant impact on the $Q^2$-dependence of the form factors.