QCD Sum Rules and the Determination of Leading Twist Non-Singlet   Operator Matrix Elements
  We use QCD sum rules to determine directly the leading-twist non-singlet operator matrix elements based on calculations of three-point correlator functions in configuration space. We find a different result from that obtained by integrating the structure functions' expressions obtained by Belyaev and Ioffe based on calculations of four-point correlators in momentum space. The origin of this discrepancy remains unclear. 
N. Chamoun (University of Oxford)