Axial Currents of Virtual Charm in Light Quark Processes

The systematic investigations of the role of the virtual charm axial currents in the decay of B-mesons to η ′ K and the spin structure of the nucleon are performed. We reduce the divergence of the virtual charm axial current to a specific gluon operator. Since this operator receives the main contribution from topologically nontrivial components of the QCD vacuum, we rederive the Diakonov-Petrov Effective Action, based on the instanton QCD vacuum model. This action is applied to the calculations of the coupling of η ′ to the charm axial current and found f (c) η ′ (µ ≃ m c) = −(12.3 ∼ 18.4 MeV), providing a possibility for the explanations of the recent experimental data on B → η ′ K-decay. Analogous calculations of the virtual charm content of the nucleon spin leads to ∆c(µ ≃ m c) = − (0.015 ∼ 0.024), which is one order of magnitude smaller than the analogous contribution of the strange quark.