QCD form factors and hadron helicity nonconservation

Recent data for the ratio R(Q)=QF₂(Q²)/F₁(Q²) surprised the community by disobeying expectations held for 50 years. It was widely thought that R(Q)~1/Q was also a rigorous prediction of PQCD. We examine the status of perturbative QCD predictions for helicity-flip form factors. Contrary to common belief, we find there is no rule of hadron helicity conservation for form factors. Numerical calculations support asymptotic analysis and extend it to the regime of laboratory momentum transfer Q². Quark orbital angular momentum, an important feature of the helicity flip processes, may play a role in all form factors at large Q², depending on the quark wave functions.