Reggeon exchange from AdS/CFT Original Research Article

Using the AdS/CFT correspondence in a confining background and the worldline formalism of gauge field theories, we compute scattering amplitudes with an exchange of quark and antiquark in the t-channel corresponding to reggeon exchange. It requires going beyond the eikonal approximation, which was used when studying pomeron exchange. The wordline path integral is evaluated through the determination of minimal surfaces and their boundaries by the saddle-point method at large gauge coupling g2Nc. We find a Regge behaviour with linear Regge trajectories. The slope is related to the qq̄ static potential and is four times the pomeron slope obtained in the same framework. A contribution to the intercept, related to the Lüscher term, comes from the fluctuations around the minimal surface.