Sum rule for deep-inelastic electroproduction from polarized protons

Abstract

A sum rule is derived for the asymmetry in deep-inelastic scattering of polarized electrons from polarized protons: $\ensuremath{\int}{0}^{1}d\ensuremath{\xi}{g}^{\mathrm{ep}}(\ensuremath{\xi})\ensuremath{\approx}0.15{g}_{A}$. The result follows from the quark light-cone algebra and the assumption that strange quarks do not contribute to the asymmetry. The latter is justified by conventional parton-model arguments.