DETERMINATION OF QCD RUNNING COUPLING CONSTANT IN NNLO APPROXIMATION, USING COMPLETE RG IMPROVEMENT

To obtain the improved QCD predictions for the moments of the xF₃ structure function in νN scattering, three-loop Wilson coefficients with the corresponding NNLO anomalous dimension coefficients is used. A comparison between QCD predictions and the xF₃ data of the CCFR collaboration has been done in which the Bernstein Polynomial method is used in the complete renormalization group improvement approach. A direct fits for over the corresponding range of Q² with five effective quark flavours, is performed.