The Determination of s ( MZ ) , Higher Twistsand xF 3 Parameterization from CCFR

The improved next-to-next-to-leading order (NNLO) QCD analysis of the experimental data of the CCFR collaboration for the xF 3 structure function is made. Theoretical ambiguities of the NNLO ts are estimated by means of the Pad e resummation technique. The NNLO and the new N 3 LO s (Q 2) MS-matching conditions are used. In the process of the ts we are taking into account the the twist-4 1=Q 2-terms. Our NNLO results for s (M Z) values, extracted from the CCFR xF 3 data, are s (M Z) = 0:118 0:002(stat) 0:005(syst) 0:004(theory) provided the twist-4 contributions are xed through the infrared renormalon model and s (M Z) = 0:116 +0:006 ?0:007 (stat) 0:005(syst) 0:004(theory) provided the twist-4 terms are considered as the free parameters. It is shown that the extracted at the NNLO order x-shape of the twist-4 correction is almost unchanged after application of the Pad e resummation approximant.