Improved nonsinglet QCD analysis of fixed-target DIS data

Deep inelastic scattering data on F-2 structure function obtained by BCDMS, SLAC and NMC collaborations in fixed-target experiments are analyzed in the non-singlet approximation with next-to-next-to-leading-order accuracy. The strong coupling constant is found to be alpha(s)(M-Z(2)) = 0.1157 +/- 0.0022 (total exp. error) + {(+0.0028)(-0.0016) (theor), which is seen to be well compatible with the average world value. The results, obtained in the present paper by carrying out fits similar to what were performed in (B G Shaikhatdenov et al 2010 Phys. Rev. D 81 034008), with the exception for systematic errors in BCDMS data taken into account in a different way, confirm our previous ones derived in that same paper. This study is also meant to at least partially explain differences in the latest predictions for LHC observables, caused by usage of different sets of parton distribution functions obtained by different groups.