The Proton Electromagnetic Form Factor $F_2$ and Quark Orbital Angular Momentum

Abstract

We analyze the proton electromagnetic form factor ratio $R(Q^2)=Q{F}_2(Q^2)/F_1(Q^2)$ as a function of momentum transfer $Q^2$ within perturbative QCD. We find that the prediction for $R(Q^2)$ at large momentum transfer $Q$ depends on the exclusive quark wave functions, which are unknown. For a wide range of wave functions we find that $Q{F}_2/F_1\sim const$ at large momentum transfer, in agreement with recent JLAB data.

Comments: 8 pages, 2 figures. To appear in Proceedings of the Workshop QCD 2002, IIT Kanpur, 18-22 November (2002)