On the value of $\alpha_s$ from the analysis of the SLAC/BCDMS deep inelastic scattering data

Abstract

We performed NLO QCD analysis of the nonsinglet part of the combined SLAC/BCDMS data on $F_2$ with the extraction of $\alpha_s$ and high twist contribution. It was shown that the value of $\alpha_s$ obtained in the analysis is sensitive to the statistical inference procedures dealing with systematic errors on the data. The fit with the complete account of point-to-point correlations of the data gave the value of $\alpha_s(M_Z)=0.1180\pm0.0017 (68% C.L.)$, to be compared with the previously reported value of $\alpha_s(M_Z)=0.113\pm0.003 (99% C.L.)$. This new value of $\alpha_s$ is compatible with the LEP measurements and the world average. The high twist contribution being strongly anti-correlated with the value of $\alpha_s$ became lower than it was previously reported.