The QCD analysis of the CCFR data for $x{F}_3$: higher twists and ${\alpha }_s(M_Z)$ extractions at the NNLO and beyond

Abstract

The improved next-to-next-to-leading order (NNLO) QCD analysis of the experimental data of the CCFR collaboration for the $x{F}_3$ structure function is made. Theoretical ambiguities of the NNLO fits are estimated by means of the Padé resummation technique, which was applied both in the expanded and non-expanded forms. The NNLO and the new N${}^3$LO ${\alpha }_s(Q^2)$ $\overline{MS}$-matching conditions are used. In the process of the fits we are taking into account the target mas corrections and the twist-4 $1/Q^2$-terms. Our NNLO results for ${\alpha }_s(M_Z)$ values, extracted from the CCFR $x{F}_3$ data, are ${\alpha }_s(M_Z)=0.118\pm 0.002(stat)\pm 0.005(syst)\pm 0.003(theory)$ provided the twist-4 contributions are fixed through the infrared renormalon model and ${\alpha }_s(M_Z)=0.116_{-0.007}^{+0.006}(stat)\pm 0.005(syst)\pm 0.004(theory)$ 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 Padé resummation approximant.

Comments: LaTeX, 21 pages, 1 figure