Polarized structure functions from the lattice

TL;DR

This paper reviews lattice calculations of polarized structure functions, introduces a chiral symmetry-preserving fermion technique, and presents preliminary nucleon spectrum results showing promising mass splittings.

Contribution

It introduces domain wall fermions for lattice calculations, enabling more accurate nucleon structure function studies with preserved chiral symmetry.

Findings

Large N and N* mass splitting observed, consistent with experiment

Preliminary results support feasibility of lattice calculations for nucleon structure functions

Domain wall fermions improve chiral symmetry preservation in lattice QCD

Abstract

We give a brief sketch of lattice structure function calculations and review previous results for the axial coupling $g_A$. We outline a new technique for treating fermions on the lattice that preserves chiral symmetry, domain wall fermions. Finally, we give preliminary results for the nucleon spectrum using this new technique. Remarkably, a large mass splitting between the $N$ and $N^*$, roughly consistent with experiment, is produced in the calculation. These results are encouraging for proposed calculations of nucleon structure functions.