Gluon polarization in nucleon

In the context of the so-called valon model, we calculate δgg and show that although it is small and compatible with the measured values, the gluon contribution to the spin of nucleon can be sizable. The smallness of δgg in the measured kinematical region should not be interpreted as δg being small. In fact, δg itself at small x, and the first moment of the polarized gluon distribution in the nucleon, Δg(Q2), are large.