Instanton-induced charm contribution to polarized deep-inelastic scattering

Recent data on B decays involving η′ may be explained if the singlet axial current of charmed quarks has a large matrix element to η′, and instantons were shown to be able to generate this effect. We study the magnitude of charm contributions to nucleon polarized structure functions generated in a similar way. Comparing the charm contribution, which is related to a dim(6) gluonic operator, to that of light quarks, which are related by the anomaly equation to GG̃, we found that Δc/ΔΣ≃−0.03. Future experiments like COMPASS at CERN identifying charm production in DIS can measure this “intrinsic polarized charm” component of the nucleon.