Non-singlet QCD analysis of deep inelastic world data at image Original Research Article

A non-singlet QCD analysis of the structure function image in LO, NLO, NNLO and N3LO is performed based on the world data for charged lepton scattering. We determine the valence quark parton densities and present their parameterization and that of the correlated errors in a wide range of x and image. In the analysis we determined the QCD-scale image, image, with a remainder uncertainty of image for the yet unknown 4-loop anomalous dimension, corresponding to image. A comparison is performed to other determinations of the QCD scale and image in deeply inelastic scattering. The higher twist contributions of image and image are extracted in the large x region, subtracting the twist-2 contributions obtained in the NLO, NNLO and N3LO analysis.