• DOI:10.1140/epjc/s10052-009-1164-2
• Corpus ID: 18567460

Uncertainties on αS in global PDF analyses and implications for predicted hadronic cross sections

@article{Martin2009UncertaintiesO,
  title={Uncertainties on $\alpha$S in global PDF analyses and implications for predicted hadronic cross sections},
  author={A D Martin and William James Stirling and Robert Samuel Thorne and Graeme Watt},
  journal={The European Physical Journal C},
  year={2009},
  volume={64},
  pages={653-680}
}

• A. Martin, W. Stirling, +1 author G. Watt
• Published 21 May 2009
• Physics
• The European Physical Journal C

AbstractWe determine the uncertainty on the strong coupling αS due to the experimental errors on the data fitted in global analysis of hard-scattering data, within the standard framework of leading-twist fixed-order collinear factorisation in the
$\overline{\mathrm{MS}}$
scheme, finding that αS(MZ2)=0.1202−0.0015+0.0012 at next-to-leading order (NLO) and αS(MZ2)=0.1171−0.0014+0.0014 at next-to-next-to-leading order (NNLO). We do not address in detail the issue of the additional theory uncertainty on αS(MZ2), but an estimate is ±0.003 at NLO and at most ±0.002 at NNLO. We investigate the interplay between uncertainties on αS and uncertainties on parton distribution functions (PDFs). We show, for the first time, how both these sources of uncertainty can be accounted for simultaneously in calculations of cross sections, and we provide eigenvector PDF sets with different fixed αS values to allow further studies by the general user. We illustrate the application of these PDF sets by calculating cross sections for W, Z, Higgs boson and inclusive jet production at the Tevatron and LHC.