MSTW PDFs and impact of PDFs on cross sections at Tevatron and LHC

Abstract

We briefly summarise the "MSTW 2008" determination of parton distribution functions (PDFs), and subsequent follow-up studies, before reviewing some topical issues concerning the PDF dependence of cross sections at the Tevatron and LHC. We update a recently published study of benchmark Standard Model total cross sections (W, Z, gg->H and t-tbar production) at the 7 TeV LHC, where we account for all publicly available PDF sets and we compare to LHC data for W, Z, and t-tbar production. We show the sensitivity of the Higgs cross sections to the gluon distribution, then we demonstrate the ability of the Tevatron jet data, and also the LHC t-tbar data, to discriminate between PDF sets with different high-x gluon distributions. We discuss the related problem of attempts to extract the strong coupling alpha_S from only deep-inelastic scattering data, and we conclude that a direct data constraint on the high-x gluon distribution is required to obtain a meaningful result. We therefore discourage the use of PDF sets obtained from "non-global" fits where the high-x gluon distribution is not directly constrained by data.

20 pages, 16 figures. To appear in the proceedings of the Ringberg Workshop on "New Trends in HERA Physics 2011", Ringberg Castle, Tegernsee, Germany, 25-28 September 2011

References in corpus (22)

• Parton distributions for the LHC
• New parton distributions for collider physics
• Implications of CTEQ global analysis for collider observables
• Vector boson production at hadron colliders: a fully exclusive QCD calculation at NNLO
• -- HATHOR -- HAdronic Top and Heavy quarks crOss section calculatoR
• Top-pair production at hadron colliders with next-to-next-to-leading logarithmic soft-gluon resummation
• Electroweak gauge boson production at hadron colliders through O(alpha_s^2)
• FEWZ 2.0: A code for hadronic Z production at next-to-next-to-leading order
• The PDF4LHC Working Group Interim Recommendations
• Hadronic top-quark pair production with NNLL threshold resummation
• Measurement of the inclusive jet cross section in $p\bar{p}$ collisions at $\sqrt{s}=1.96\mathrm{TeV}$
• The PDF4LHC Working Group Interim Report
• Measurement of the inclusive W+- and Z/gamma cross sections in the electron and muon decay channels in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector
• Dynamical parton distributions of the nucleon and very small-x physics
• Heavy-quark mass dependence in global PDF analyses and 3- and 4-flavour parton distributions
• Fixed target Drell-Yan data and NNLO QCD fits of parton distribution functions
• On the role of heavy flavor parton distributions at high energy colliders
• Precision NNLO determination of alpha_s(M_Z) using an unbiased global parton set
• Theory-Data Comparisons for Jet Measurements in Hadron-Induced Processes
• The Tevatron Higgs exclusion limits and theoretical uncertainties: a critical appraisal
• Parton distributions and Tevatron jet data
• The effects of combined HERA and recent Tevatron W - > lepton neutrino charge asymmetry data on the MSTW PDFs

Cited by in corpus (9)

• Higgs boson mass and new physics
• Quantitative constraints on the gluon distribution function in the proton from collider isolated-photon data
• Progress in the Determination of the Partonic Structure of the Proton
• Parton Distribution Benchmarking with LHC Data
• Study of Monte Carlo approach to experimental uncertainty propagation with MSTW 2008 PDFs
• Constraints on the gluon PDF from top quark pair production at hadron colliders
• Top Quark Physics at the LHC: A Review of the First Two Years
• Limit setting procedures and theoretical uncertainties in Higgs boson searches
• Physics potential of precision measurements of the LHC luminosity