Nucleon structure functions from dynamical (2+1)-flavor domain wall fermions

Understand

We report lattice-volume independence of low moments of nucleon structure functions from the coarse RIKEN-BNL-Columbia (RBC) and UKQCD joint dynamical (2+1)-flavor domain-wall fermions (DWF) ensembles at the lattice cut off of (a^{-1}\sim1.7) GeV.

• The isovector quark momentum fraction, (< x >_{u-d}), and helicity fraction, (< x >_{\Delta u - \Delta d}), both fully non-perturbatively renormalized are studied on two spatial volumes of ((\sim {\rm 2.7 fm})^3) and ((\sim {\rm 1.8 fm})^3).
• Their naturally renormalized ratio, (< x >_{u-d}/< x >_{\Delta u - \Delta d}), is not affected by any finite-size effect.
• It does not depend strongly on light quark mass and does agree well with the experiment.