Nucleon structure in the chiral regime with domain wall fermions on an improved staggered sea

TL;DR

This paper presents lattice QCD calculations of nucleon structure observables using domain wall fermions on an improved staggered sea, providing insights into the nucleon's transverse structure and spin content.

Contribution

It introduces a mixed action lattice approach with domain wall valence quarks on an improved staggered sea and analyzes nucleon structure at near-physical pion masses.

Findings

Results agree with experimental moments of quark distributions.

Chiral extrapolations inform nucleon transverse structure.

Implications for nucleon spin content are discussed.

Abstract

Moments of unpolarized, helicity, and transversity distributions, electromagnetic form factors, and generalized form factors of the nucleon are presented from a preliminary analysis of lattice results using pion masses down to 359 MeV. The twist two matrix elements are calculated using a mixed action of domain wall valence quarks and asqtad staggered sea quarks and are renormalized perturbatively. Several observables are extrapolated to the physical limit using chiral perturbation theory. Results are compared with experimental moments of quark distributions and electromagnetic form factors and phenomenologically determined generalized form factors, and the implications on the transverse structure and spin content of the nucleon are discussed.