Soft Pomeron in Holographic QCD

TL;DR

This paper models the soft pomeron in high energy scattering using holographic QCD, constructing a Regge trajectory for glueball states that aligns with experimental soft pomeron parameters.

Contribution

It introduces a model for the graviton Regge trajectory in holographic QCD, extending the spin J field equation to the real J < 2 region, matching observed soft pomeron data.

Findings

Regge trajectories are approximately linear.

Intercept matches the measured value of 1.08.

Slope aligns with the observed 0.25 GeV$^{-2}$.

Abstract

We study the graviton Regge trajectory in Holographic QCD as a model for high energy scattering processes dominated by soft pomeron exchange. This is done by considering spin J fields from the closed string sector that are dual to glueball states of even spin and parity. In particular, we construct a model that governs the analytic continuation of the spin J field equation to the region of real J < 2, which includes the scattering domain of negative Maldelstam variable t. The model leads to approximately linear Regge trajectories and is compatible with the measured values of 1.08 for the intercept and 0.25 GeV$^{-2}$ for the slope of the soft pomeron. The intercept of the secondary pomeron trajectory is in the same region of the subleading trajectories, made of mesons, proposed by Donnachie and Landshoff, and should therefore be taken into account.