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 ${\alpha }_s(M_Z)=0.1180\pm 0.0017(68$, to be compared with the previously reported value of ${\alpha }_s(M_Z)=0.113\pm 0.003(99$. 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.

Comments: 9 pages, LATEX, 2 figures (PS), report-no added, English improved, misprints corrected, minor changes of the text