QCD Sum Rule Analysis of Leading Twist Non-Singlet Operator Matrix   Elements
  We use QCD sum rules to determine the difference between moments of the non-singlet structure functions. This combination decouples from the singular behaviour of the structure functions near x=1 as calculated in the quark-gluon basis and thus should lead to improved sum rule predictions. However, we find there are still very large errors due to higher order corrections. In order to refine the error analysis, we study the effect of renormalon ambiguities on our QCD sum rules results. 
N. Chamoun, G.G. Ross (University of Oxford)