Parton model and the Bethe-Salpeter wave function

The quark-parton model is discussed from the point of view that the quark partons are the quanta created by the Fourier transforms of the quark fields at constant x⁺. We argue using this picture that, for a given behavior of a hadron's deep-inelastic structure function W₂(x) as x→1, the Drell-Yan-West relation provides a lower bound on the behavior of its form factor F₁(Q²) as Q²→∞. The connection between the parton and Bethe-Salpeter descriptions of hadron structure is described and used to translate known information about the pion's Bethe-Salpeter wave function into information about the amplitude for a pion to consist of precisely two quark partons. We find that the two-parton contributions to νW₂(x) and F(Q²) behave roughly like νW₂∝(1-x)² for small (1-x) and F(Q²)∝(Q²)^-1 for large Q², respectively.