Hadron masses: lattice QCD and chiral effective field theory

TL;DR

This paper evaluates the reliability and challenges of chiral extrapolation in lattice QCD, analyzing nucleon, pion, and kaon masses using chiral perturbation theory and lattice data, with a focus on uncertainties and consistency checks.

Contribution

It provides a comprehensive analysis of chiral extrapolation methods, including volume dependence and SU(3)-SU(2) matching, enhancing understanding of lattice QCD results for hadron masses.

Findings

Chiral fits to nucleon mass data show statistical uncertainties and convergence issues.

Lattice volume dependence offers additional constraints for chiral extrapolations.

SU(3)-SU(2) matching reveals deviations from the Gell-Mann–Oakes–Renner relation.

Abstract

This work discusses reliability, possible obstacles and the future perspective of chiral extrapolation of lattice results. In the first part, chiral perturbation theory fits to lattice calculations of the nucleon mass are thoroughly explored in terms of statistical uncertainty and convergence. Lattice volume dependence is exploited as a source of additional fit constraints. In discussing consistency with pion-nucleon scattering, the role of the Delta(1232) excitation is clarified. In the second part of the work, pion and kaon mass lattice data are analyzed using three-flavor chiral perturbation theory. SU(3)-SU(2) matching conditions permit to examine deviations from the Gell-Mann, Oakes, Renner relation. Introductory chapters provide a quick start guide to manifestly covariant baryon chiral perturbation theory, basic understanding of lattice QCD and a self-contained explanation of the relevant statistical methods.