The 3-, 4-, and 5-flavor NNLO Parton Distributions Functions from Deep-Inelastic-Scattering Data and at Hadron Colliders

We determine the parton distribution functions (PDFs) in a next-to-next-to-leading order (NNLO) QCDanalysis of the inclusive neutral-current deep-inelastic-scattering (DIS) world data combined with the neutrino-nucleon DIS di-muon data and the fixed-target Drell-Yan data. The PDF-evolution is performed in the N f = 3 fixed-flavor scheme and supplementary sets of PDFs in the 4and 5-flavor schemes are derived from the results in the 3-flavor scheme using matching conditions. The charm-quark DIS contribution is calculated in a general-mass variable-flavor-number (GMVFN) scheme interpolating between the zeromass 4-flavor scheme at asymptotically large values of momentum transfer Q2 and the 3-flavor scheme prescription of Buza-Matiounine-Smith-van Neerven (BMSN) at the value of Q2 = mc . The results in the GMVFN scheme are compared with those of the fixed-flavor scheme and other prescriptions used in global fits of PDFs. The strong coupling constant is measured at an accuracy of ≈ 1.5%. We obtain at NNLO αs(M Z) = 0.1135± 0.0014 in the fixed-flavor scheme and αs(M 2 Z) = 0.1129± 0.0014 applying the BMSNprescription. The implications for important standard candle and hard scattering processes at hadron colliders are illustrated. Predictions for cross sections of W±and Z-boson, the top-quark pairand Higgs-boson production at the Tevatron and the LHC based on the 5-flavor PDFs of the present analysis are provided. 1e-mail: [email protected] 2e-mail: [email protected] 3e-mail: [email protected] 4e-mail: [email protected]