Polarized nonsinglet {Delta q}_3 and nonsinglet fragmentation function D^{pi+}_{u_v} in the analytic approach to QCD

Abstract

We discuss the application of an analytic approach called the analytic perturbation theory (APT) to the QCD analysis of DIS data. In particular, the results of the QCD analysis of a set of `fake' data on the polarized nonsinglet Delta{q3} and the nonsinglet fragmentation function D^{pi+}_{u_v} by using the Q^2-evolution within the APT are considered. The `fake' data are constructed based on parametrization of the polarized PDF and nonsinglet combination of the pion fragmentation functions. We confirm that APT can be successfully applied to QCD analysis of Delta{q_3}(x,Q^2) and D^{pi+}_{u_v}(z,Q^2) and that the inequality Lambda_{APT} > Lambda_{PT} obtained previously for the xF3(x) structure function takes place.