Value of αsfrom deep-inelastic-scattering data

We report the value of $\alpha_{\rm s}$ obtained from QCD analysis ofexisting data on deep-inelastic scattering of charged leptons off proton anddeuterium and estimate its theoretical uncertainties with particular attentionpaid to impact of the high-twist contribution to the deep-inelastic-scatteringstructure functions. Taking into account the major uncertainties the value$\alpha^{\rm NNLO}_{\rm s}(M_{\rm Z})=0.1143 \pm 0.0014({\rm exp.})\pm0.0013({\rm theor.})$ is obtained. An extrapolation of the LO--NLO--NNLOresults to the higher orders makes it possible to estimate $\alpha^{\rmN^3LO}_{\rm s}(M_{\rm Z})\sim 0.113$.Comment: 9 pages, LATEX, 4 figures (EPS). Talk given at 16th International Baldin Seminar on High-Energy Physics Problems: Relativistic Nuclear Physics and Quantum Chromodynamics (ISHEPP 16), Dubna, Russia, 10-15 Jun 200; v2: typos corrected, layout improved, 2 references adde