How much momentum do gluons actually carry in a proton?

Physicists used lattice QCD—essentially solving quantum chromodynamics on a discrete grid—to measure how gluons distribute energy and momentum inside protons. By calculating matrix elements of nonlocal operators, they extracted ratios of higher-order gluon moments, pinning down the ratio ⟨x³⟩/⟨x⟩ at 2 GeV. This is fundamental input for understanding proton structure and improving predictions for collider experiments.