Asymptotic Behavior of Feynman Integrals with Spin

Some general features are investigated of the dependence of the asymptotic behavior of Feynman integrals upon factors in the numerator of the integrand resulting from particles with spin. These results are used to analyze the high-energy behavior of ladder diagrams for $\mathrm{spin}-\frac{1}{2}$ nucleons interacting with neutral vector mesons. The leading contribution is shown to consist of terms corresponding to a reggeised nucleon together with certain other terms. The expected cancellation of these other terms by terms associated with a well-defined class of crossed diagrams is verified in detail for the sixth-order case. Finally, other significant diagrams, different from the ladders and their associated crossed diagrams, are investigated and it is shown that they only provide higher-order corrections to the trajectory of the reggeised nucleon.