The gluon/charm content of the eta' meson and instantons

Abstract

Motivated by recent CLEO measurements of the B-->η' K decay, we evaluate gluon/charm content of the eta' meson using the interacting instanton liquid model of the QCD vacuum. Our result is very large due to the strong field of small-size instantons. We show that it provides quantitative explanations of the CLEO data on the B-->η' K decay rate (as well as inclusive process B-->η' X), via a virtual Cabbibo-unsuppressed decay into \bar c c pair which then becomes eta'. If so, a significant charm component should be present in other hadrons also. In particular, we found a large contribution of the charmed quark in the polarised deep-inelastic scattering on a proton.