Uncertainties of predictions from parton distributions I: Experimental errors

By Alan D. Martin, R. G. Roberts, W. Stirling, R. Thorne. 2002

321 citations recorded by the source corpus.

Abstract. We determine the uncertainties on observables arising from the errors on the experimental data that are fitted in the global MRST2001 parton analysis. By diagonalizing the error matrix we produce sets of partons suitable for use within the framework of linear propagation of errors, which is the most convenient method for calculating the uncertainties. Despite the potential limitations of this approach we find that it can be made to work well in practice. This is confirmed by our alternative approach of using the more rigorous Lagrange multiplier method to determine the errors on physical quantities directly. As particular examples we determine the uncertainties on the predictions of the charged-current deep-inelastic structure functions, on the cross-sections for W production and for Higgs boson production via gluon-gluon fusion at the Tevatron and the LHC, on the ratio of W- to W+ production at the LHC and on the moments of the non-singlet quark distributions. We discuss the corresponding uncertainties on the parton distributions in the relevant x,Q2 domains. Finally, we briefly look at uncertainties related to the fit procedure, stressing their importance and using $\sigma_W$, $\sigma_H$ and extractions of $\alpha_S(M_Z^2)$ as examples. As a by-product of this last point we present a slightly updated set of parton distributions, MRST2002.

Subfields: Artificial Intelligence, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/8a7b9d4b79442a826b8df3a0d549d8c77fcbb650

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Citations in the corpus

A Positive-weight next-to-leading-order Monte Carlo for heavy flavour hadroproduction (2007, methodology): “We have used the MRST2002 [14] set of parton distributions.”
Standard Model Higgs boson production in association with a top anti-top pair at NLO with parton showering (2011, methodology): “choices [31], and in all cases we found agreement up to 5{6 digits. 3 We then compared the cross-sections at the NLO accuracy to the predictions of Ref. [26]. At this purpose, we used the MRST2002nlo [32] PDF set, provided by LHAPDF [33], with a 2-loop running MS s, 5 light avours and 5 = 239MeV, an”
Handbook of LHC Higgs Cross Sections: 3. Higgs Properties (2013, result): “it was also shown that higher twist corrections to the DIS data incl uded in the NNPDF PDF determination have a negligible impact on all PDFs, similar to previous conclus ion by MRST [227] and more recent studies involving MSTW PDFs.”
The PDF4LHC report on PDFs and LHC data: Results from Run I and preparation for Run II (2015, methodology): “The impact of the inclusive jet measurement on the PDFs of the proton is investigated in detail using the HERAFitter tool [47], using both the Hessian [181] and the Monte Carlo methods [182].”
Progress in the Determination of the Partonic Structure of the Proton (2013, methodology): “A comprehensive study of the PDF dependence of key LHC cross sections has recently been made in Reference [45], following earlier work in References [42–44].”