Scattering Amplitudes in Quantum Electrodynamics at Infinite Energy, and Possible Implications for Hadron Physics

We study in pure quantum electrodynamics the scattering amplitudes at infinite energy due to multiphoton exchange, with interactions among the exchange photons. Such processes, elastic or inelastic, lead to logarithmic dependence on s. The lns dependence is found to be associated with the invariance of subgraphs under a boost along the direction of the high-energy collision. Theoretically, our results lead towards a more efficient way of handling a large class of diagrams, and a better understanding of j-plane cut behavior. We speculate that several features of our results generalize to hadron physics. Among these are features in common with the limiting fragmentation hypothesis, and the appearance of pionization in a many-fireball structure. Finally, in the absence of radiative corrections, we demonstrate that the e^-, e^∓ elastic scattering amplitude can be expressed as an eikonal form, with χ(b) being generated by the sum of all connected pieces.