Perturbative stability of the QCD analysis of DIS data

We perform pQCD analysis of the existing DIS data for charged leptons with account of corrections up to the NNLO. The parton distributions, value of strong coupling constant, and high-twist terms are extracted and their stability with respect to account of the NNLO corrections is analyzed. All the quantities are generally stable within their experimental errors. Obtained value of the strong coupling constant is $\alpha_s^{\rm NNLO}(M_{\rm Z})=0.1143\pm 0.0014 ({\rm exp})$ with a guess $\alpha_s^{\rm NNNLO}(M_{\rm Z})\sim 0.113$.