Proton helicity structure function g_1^p from a holographic Pomeron

Abstract

We present a detailed analysis of the polarized and the unpolarized deep inelastic scattering structure functions of the proton, g_1^p and F_2^p respectively, in the context of a holographic dual description based on type IIB superstring theory. We compare this description with experimental data and Quantum Chromodynamics estimates computed at leading, next-to-leading and next-to-next-to-leading order in perturbation. We confront the predictions of a holographic dual model and those of perturbative QCD for g_1^p at the kinematics that will be probed by the forthcoming Electron-Ion Collider. We find that the extrapolation of g_1^p to very small values the Bjorken variable computed with a Holographic Pomeron model based on actual data at higher momentum fractions is always positive and differs significantly with standard projections based on perturbative QCD.

34 pages, 3 figures, a few corrections, new references, version to appear in Physical Review D