Pomeron contribution toppandpp¯scattering in AdS/QCD

Abstract

We consider the differential and total cross sections for proton-proton and proton-antiproton scattering in the Regge regime from the point of view of string dual models of QCD. We argue that the form factor which appears in the differential cross section is related to the matrix element of the stress tensor between proton states and give a procedure for computing the strength of the coupling of the Pomeron trajectory to the proton. We compute this coupling in the Sakai-Sugimoto model and find excellent agreement with the data at large $s$ and small $t$. The form factor can be estimated in the Skyrme model or in AdS/QCD models and gives a stiffer form factor than the commonly used electromagnetic form factor, in agreement with our fits to data. Our model is also in good agreement with the measured ratio of real to imaginary parts of the forward scattering amplitude at large $s$.