Purely-Nonperturbative Composite Operators and Parton Distributions

A class of purely-nonperturbative (PNP) composite operators is defined in Quantum Chromodynamics, which is perturbative scheme and scale independent and are useful to describe the internal structure of a strong interacting system. The operator product expansion in terms of the new operators cleanly separates the perturbative and nonperturbative physics without introducing any factorization scale. A number of PNP observables of the nucleon is briefly discussed including the PNP parton distributions. In particular, the fraction of the nucleon momentum carried by the purely-nonperturbative gluons is found to be around 16%.