  The absence of "valence-gluon" degrees of freedom combined with an
examination of radiative QCD diagrams leads to an implication that the gluon
spin asymmetry in a proton, defined as A_G(x,Q^2) = (Delta G)/G, should be
approximately Q^2 invariant. The condition for scale invariance completely
determines the x-dependence of this asymmetry, which satisfies the constituent
counting rules and reproduces the basic results of the Bremsstrahlung model
originated by Close and Sivers. This asymmetry can be combined with the
measured unpolarized gluon density, G(x,Q^2) to provide a prediction for Delta
G(x,Q^2). Existing and proposed experiments can test both the prediction of
scale invariance for A_G and the nature of Delta G itself.

High Energy Physics - Phenomenology