Fixed wide-angle scattering of elementary fermions in gauge theories

We consider leading logarithmic corrections to the Born amplitude for wide-angle scattering of off-mass-shell quarks through sixth order in non-Abelian gauge theories. We review first the situation for the case of Abelian theories, where the leading logarithmic contributions can be summed to all orders, yielding a simple exponential form ${\mathrm{e}}^{-K{\ln }^{2}t}$. We find that the non-Abelian theory, through fourth order, yields a form corresponding to the perturbation expansion of an exponential. A partial computation of the sixth order suggests that such an expansion may still hold in that order.