Proton Spin Structure from Lattice QCD

Abstract

A lattice QCD calculation of the proton matrix element of the flavor singlet axial-vector current is reported. Both the connected and disconnected contributions are calculated, for the latter employing the variant method of wall source without gauge fixing. From simulations in quenched QCD with the Wilson quark action on a $16^3\times 20$ lattice at $\beta =5.7$ (the lattice spacing $a\approx 0.14$fm), we find $\Delta \Sigma =\Delta u+\Delta d+\Delta s=+0.638(54)-0.347(46)-0.109(30)=+0.18(10)$ with the disconnected contribution to $\Delta u$ and $\Delta d$ equal to $-0.119(44)$, which is reasonably consistent with the experiment.

10 pages as latex dvi-file, two figures as ps-file, uuencoded compressed tar file

References in corpus (5)

• Measurement of the Spin-Dependent Structure Function $g_1(x)$ of the Proton
• Determination of ${\alpha }_s$ and the Nucleon Spin Decomposition Using Recent Polarized Structure Function Data
• Nucleon Axial Form Factor from Lattice QCD
• The spin content of the proton in quenched QCD
• Matrix Elements of the Singlet Axial Current in the Proton

Cited by in corpus (74)

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