Matrix Elements of the Singlet Axial Current in the Proton

Abstract

We present a method to estimate the matrix element of the singlet axial current within a polarized proton state using lattice QCD. The method relies on using the Adler-Bell-Jackiw anomaly and gives the desired result in the chiral limit. We show that this method fails in the quenched approximation. For heavy quarks one does not expect much difference between simulations including dynamical quarks and those done in the quenched approximation. For that reason we explore numerical methods on an existing set of quenched configurations. The data obtained in this exploratory study show a poor statistical signal.

Self-contained PS file containing 19 pages. Final published version of the paper

References in corpus (1)

• Analysis of Data on Polarized Lepton-Nucleon Scattering

Cited by in corpus (10)

• Parton distributions and lattice QCD calculations: a community white paper
• FLAVOR-SINGLET g_A FROM LATTICE QCD
• Proton Spin Structure from Lattice QCD
• Improved lattice operators: the case of the topological charge density
• Flavour singlet physics in lattice QCD with background fields
• Flavor Singlet Axial Vector Coupling of the Proton with Dynamical Wilson Fermions
• Topological charge density renormalization in the presence of dynamical fermions
• Polarized Parton Distribution Functions Reexamined
• Evolution of the spin of the nucleon
• The spin content of the proton in full QCD