Extrapolations of Lattice Meson Form Factors

TL;DR

This paper uses chiral perturbation theory to analyze how to accurately extrapolate lattice QCD data for pseudoscalar meson form factors, considering various dependencies to improve physical predictions.

Contribution

It provides a detailed framework for extrapolating lattice QCD results, accounting for quark mass, momentum, lattice spacing, and volume effects, especially for mixed action simulations.

Findings

Finite volume effects are significant in charge radius extrapolations.

Most systematic errors arise from finite volume corrections.

Extrapolations to infinite volume are crucial for accurate results.

Abstract

We use chiral perturbation theory to study the extrapolations necessary to make physical predictions from lattice QCD data for the electromagnetic form factors of pseudoscalar mesons. We focus on the quark mass, momentum, lattice spacing, and volume dependence and apply our results to simulations employing mixed actions of Ginsparg-Wilson valence quarks and staggered sea quarks. To determine charge radii at quark masses on the lattices currently used, we find that all extrapolations except the one to infinite volume make significant contributions to the systematic error.