Measuring the Triple-Gluon Vertex

It is proposed to measure the deep-inelastic longitudinal structure function $F_L(x,Q^2)$, or moments thereof, in order to determine the $Q^2$ dependence of the gluon distribution. In contrast to $F_2(x,Q^2)$, the theoretical predictions for the $Q^2$ evolution of the moments of the gluon density depend critically on the gluon self-couplings and thus provide us with a sensitive test of the Yang-Mills structure of quantum chromodynamics.