We propose a model-independent method to ascertain the leading valence composition of a hadron: to measure the energy dependence of its production cross section at a fixed angle interval. This E-dependence, by the QCD Brodsky-Farrar counting rules, falls at high energy with a steepness that depends on the leading quark and gluon composition.
We exemplify with a reaction that could help classify the f0 mesons, exclusive e-e+ -> phi + f0
with an easily reconstructible final state. Some of the f0 may have a glueball gg component in their wavefunction decomposition; this will dominate at high energy over higher twist quark-antiquark components (because they necessarily have a p-wave) or hybrid/tetraquark components (because of the higher number of particles in the final state). We discuss the prospects to carry out this or similar analysis in Belle II.