PDF uncertainties in Higgs production at hadron colliders

Abstract

Using the new schemes provided by the CTEQ and MRST collaborations and by Alekhin, we analyse the uncertainties due to the parton distribution functions (PDFs) on the next-to-leading-order cross sections of the four main production processes of the Standard Model Higgs boson at the LHC and the Tevatron. In the Higgs mass range where the production rates are large enough, the spread in the uncertainties when the three sets of PDFs are compared is of about 15% in all processes and at both colliders. However, within one given set of PDFs, the deviations from the values obtained with the reference sets are much smaller, being of ${\cal O}(5$%), except in the gluon--gluon fusion mechanism at relatively large Higgs boson masses, where they can reach the level of 10% (15%) at the LHC (Tevatron).

Figures (5)

• Figure 1: The NLO cross sections for Higgs production at the LHC (left) and the Tevatron (right) as a function of the Higgs mass. The reference CTEQ6M set is used.
• Figure 2: MRST and Alekhin densities for the gluon, up quark/down quark and antiquarks, normalized to the CTEQ6 ones, as a function of $x$ and for $Q^2=(100\ {\rm GeV})^2$.
• Figure 3: The CTEQ, MRST and Alekhin PDF uncertainty bands for the NLO cross sections for the production of the Higgs boson at the LHC (left) and at the Tevatron (right) in the $q\bar{q} \to HW$ process. The insets show the spread in the predictions, when the NLO cross sections are normalized to the prediction of the reference CTEQ6M set.
• Figure 4: Same as Fig. 3, but for the $gg \to H$ production process.
• Figure 5: Same as Fig. 3, but for the $qq \to Hqq$ and $pp \to ttH$ processes at the LHC.