Almost-Infinite-Momentum Frame and High-Energy Scattering Processes

A useful frame for studying high-energy scattering is introduced. It is a rotation of the usual space-time coordinate in the $\mathrm{zt}$ plane by the angle $\frac{1}{4}\pi -\frac{1}{2}\gamma$ in the limit $\gamma \to 0$. The structure functions $W(\kappa ,\nu )$ for scattering processes in the limits of infinite momenta are considered in this special frame. By linking the limiting process $\gamma \to 0$ with that of infinite momentum, it is shown that $W(\kappa ,\nu )$ is scaled if $\nu \to \infty$ and $\kappa \ne 0$ (not necessarily large). Moreover, the region of validity for the scaling law is established and is found to be consistent with experiments.