Polarized deep inelastic and elastic scattering from gauge/string duality

Abstract

In this paper, we investigate deep inelastic and elastic scattering on a polarized spin-$\frac{1}{2}$ hadron using gauge/string duality. This spin-$\frac{1}{2}$ hadron corresponds to a supergravity mode of the dilatino. The polarized deep inelastic structure functions are computed in the supergravity approximation at large t' Hooft coupling $\ensuremath{\lambda}$ and finite $x$ with ${\ensuremath{\lambda}}^{\ensuremath{-}1/2}\ensuremath{\ll}xl1$. Furthermore, we discuss the moments of all structure functions, and propose an interesting sum rule ${\ensuremath{\int}}_{0}^{1}dx{g}_{2}(x,{q}^{2})=0$ for the ${g}_{2}$ structure function which is known as the Burkhardt-Cottingham sum rule in QCD. In the end, the elastic scattering is studied and elastic form factors of the spin-$\frac{1}{2}$ hadron are calculated within the same framework.