Author/Authors :
M. G?ckeler، نويسنده , , R. R. Horsley، نويسنده , , B. Klaus، نويسنده , , D. Pleiter، نويسنده , , P.E.L. Rakow، نويسنده , , S. Schaefer، نويسنده , , A. Sch?fer، نويسنده , , G. Schierholz، نويسنده ,
Abstract :
Nucleon matrix elements of various four-quark operators are evaluated in quenched lattice QCD using Wilson fermions. Some of these operators give rise to twist-four contributions to nucleon structure functions. Furthermore, they bear valuable information about the diquark structure of the nucleon. Mixing with lower-dimensional operators is avoided by considering appropriate representations of the flavour group. We find that for a certain flavour combination of baryon structure functions, twist-four contributions are very small.
