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Related papers: Uncertainties on alpha_S in global PDF analyses an…

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We study at a quantitative level the impact of the uncertainties on the value of the W boson mass measured at hadron colliders due to: the proton parton distribution functions (PDFs), the value of the strong coupling constant alpha_S and…

High Energy Physics - Phenomenology · Physics 2011-07-05 G. Bozzi , J. Rojo , A. Vicini

We present a determination of the nucleon parton distribution functions (PDFs) and of the strong coupling constant $\alpha_s$ at next-to-next-to-leading order (NNLO) in QCD based on the world data for deep-inelastic scattering and the…

High Energy Physics - Phenomenology · Physics 2012-08-08 S. Alekhin , J. Bluemlein , S. -O. Moch

We present a determination of the parton distributions of the nucleon from a global set of hard scattering data using the NNPDF methodology: NNPDF2.0. Experimental data include deep-inelastic scattering with the combined HERA-I dataset,…

High Energy Physics - Phenomenology · Physics 2014-11-20 Richard D. Ball , Luigi Del Debbio , Stefano Forte , Alberto Guffanti , Jose I. Latorre , Juan Rojo , Maria Ubiali

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…

High Energy Physics - Phenomenology · Physics 2015-03-19 Graeme Watt

Global fits for precision determinations of parton distributions, together with the highly correlated strong coupling $\alpha_s$, are presented up to next-to-next-to-leading order (NNLO) of QCD utilizing most world data (charm and jet…

High Energy Physics - Phenomenology · Physics 2014-05-23 Pedro Jimenez-Delgado , Ewald Reya

The QCD coupling alpha_s is determined at NLO*+NMLLA accuracy from the comparison of experimental jet data to theoretical predictions of the energy-evolution of the parton-to-hadron fragmentation function moments (multiplicity, peak, width,…

High Energy Physics - Phenomenology · Physics 2014-10-20 David d'Enterria , Redamy Pérez-Ramos

The strong coupling constant $\alpha_s(M_Z)$ is determined from inclusive jet and dijet cross sections in neutral-current deep-inelastic $ep$ scattering (DIS) measured at HERA by the H1 collaboration using next-to-next-to-leading order…

High Energy Physics - Experiment · Physics 2021-06-17 H1 collaboration , V. Andreev , A. Baghdasaryan , K. Begzsuren , A. Belousov , V. Bertone , A. Bolz , V. Boudry , G. Brandt , V. Brisson , D. Britzger , A. Buniatyan , A. Bylinkin , L. Bystritskaya , A. J. Campbell , K. B. Cantun Avila , K. Cerny , V. Chekelian , J. G. Contreras , J. Cvach , J. Currie , J. B. Dainton , K. Daum , C. Diaconu , M. Dobre , V. Dodonov , G. Eckerlin , S. Egli , E. Elsen , L. Favart , A. Fedotov , J. Feltesse , M. Fleischer , A. Fomenko , E. Gabathuler , J. Gayler , T. Gehrmann , S. Ghazaryan , L. Goerlich , N. Gogitidze , M. Gouzevitch , C. Grab , A. Grebenyuk , T. Greenshaw , G. Grindhammer , C. Gwenlan , D. Haidt , R. C. W. Henderson , J. Hladky , D. Hoffmann , R. Horisberger , T. Hreus , F. Huber , A. Huss , M. Jacquet , X. Janssen , A. W. Jung , H. Jung , M. Kapichine , J. Katzy , C. Kiesling , M. Klein , C. Kleinwort , R. Kogler , P. Kostka , J. Kretzschmar , D. Krücker , K. Krüger , M. P. J. Landon , W. Lange , P. Laycock , A. Lebedev , S. Levonian , K. Lipka , B. List , J. List , B. Lobodzinski , E. Malinovski , H. -U. Martyn , S. J. Maxfield , A. Mehta , A. B. Meyer , H. Meyer , J. Meyer , S. Mikocki , A. Morozov , K. Müller , Th. Naumann , P. R. Newman , C. Niebuhr , J. Niehues , G. Nowak , J. E. Olsson , D. Ozerov , C. Pascaud , G. D. Patel , E. Perez , A. Petrukhin , I. Picuric , H. Pirumov , D. Pitzl , R. Plačakytė , R. Polifka , K. Rabbertz , V. Radescu , N. Raicevic , T. Ravdandorj , P. Reimer , E. Rizvi , P. Robmann , R. Roosen , A. Rostovtsev , M. Rotaru , D. Šálek , D. P. C. Sankey , M. Sauter , E. Sauvan , S. Schmitt , L. Schoeffel , A. Schöning , F. Sefkow , S. Shushkevich , Y. Soloviev , P. Sopicki , D. South , V. Spaskov , A. Specka , M. Steder , B. Stella , U. Straumann , M. R. Sutton , T. Sykora , P. D. Thompson , D. Traynor , P. Truöl , I. Tsakov , B. Tseepeldorj , A. Valkárová , C. Vallée , P. Van Mechelen , Y. Vazdik , D. Wegener , E. Wünsch , J. Žáček , Z. Zhang , R. Žlebčík , H. Zohrabyan , F. Zomer

In this contribution we discuss the impact of PDF uncertainties on t\bar{t} and t-channel single-top production at the LHC. We present predictions for total cross-sections computed at NLO accuracy with different PDF sets. For single- top…

High Energy Physics - Phenomenology · Physics 2022-03-02 Alberto Guffanti , Juan Rojo

The parton distributions functions (PDFs) derived from the NNLO QCD analysis of existing light-targets deep-inelastic-scattering data are presented. The NLO and NNLO PDFs are compared in order to analyze perturbative stability of the…

High Energy Physics - Phenomenology · Physics 2007-05-23 S. Alekhin

We apply the Lagrange Multiplier method to study the uncertainties of physical predictions due to the uncertainties of parton distribution functions (PDFs), using the cross section for W production at a hadron collider as an archetypal…

High Energy Physics - Phenomenology · Physics 2009-09-25 D. Stump , J. Pumplin , R. Brock , D. Casey , J. Huston , J. Kalk , H. L. Lai , W. K. Tung

We study several sources of theoretical uncertainty in the determination of parton distributions (PDFs) which may affect current PDF sets used for precision physics at the Large Hadron Collider, and explain discrepancies between them. We…

High Energy Physics - Phenomenology · Physics 2013-05-09 The NNPDF Collaboration , Richard D. Ball , Valerio Bertone , Luigi Del Debbio , Stefano Forte , Alberto Guffanti , Juan Rojo , Maria Ubiali

We perform a next-to-next-to-leading order (NNLO) analysis of nuclear parton distribution functions (nPDFs) using neutral current charged-lepton ($\ell ^\pm$ + nucleus) deeply inelastic scattering (DIS) data and Drell-Yan (DY) cross-section…

High Energy Physics - Phenomenology · Physics 2016-01-29 Hamzeh Khanpour , S. Atashbar Tehrani

The inclusive cross sections of W$^+$, W$^-$, and Z boson production from 34 different measurements performed in proton-(anti)proton collisions at center-of-mass energies $\sqrt{s}$ = 1.8--13 TeV, are compared to perturbative QCD…

High Energy Physics - Phenomenology · Physics 2020-06-04 David d'Enterria , Andres Poldaru

We show how to account for correlations between theoretical uncertainties incorporated in parton distribution function (PDF) fits, and the theoretical uncertainties in the predictions made using these PDFs. We demonstrate by explicit…

High Energy Physics - Phenomenology · Physics 2021-10-04 Richard D. Ball , Rosalyn L. Pearson

We present a determination of the parton distributions of the nucleon from a global set of hard scattering data using the NNPDF methodology at LO and NNLO in perturbative QCD, thereby generalizing to these orders the NNPDF2.1 NLO parton…

We respond to some criticism questioning the validity of the current Standard Model Higgs exclusion limits at the Tevatron, due to the significant dependence of the dominant production cross section from gluon-gluon fusion on the choice of…

High Energy Physics - Phenomenology · Physics 2011-08-26 R. S. Thorne , G. Watt

We present a first global determination of spin-dependent parton distribution functions (PDFs) and their uncertainties using the NNPDF methodology: NNPDFpol1.1. Longitudinally polarized deep-inelastic scattering data, already used for the…

High Energy Physics - Phenomenology · Physics 2015-06-22 Emanuele R. Nocera , Richard D. Ball , Stefano Forte , Giovanni Ridolfi , Juan Rojo

We present a determination of the strong coupling constant $\alpha_s(m_Z)$ using inclusive top-quark pair production cross section measurements performed at the LHC and at the Tevatron. Following a procedure first applied by the CMS…

High Energy Physics - Phenomenology · Physics 2017-12-06 Thomas Klijnsma , Siegfried Bethke , Günther Dissertori , Gavin P. Salam

Using the recently derived NNLO cross sections \cite{Czakon:2013goa}, we provide NNLO+NNLL theoretical predictions for top quark pair production based on all the available NNLO PDF sets, and compare them with the most precise LHC and…

High Energy Physics - Phenomenology · Physics 2015-06-15 Michal Czakon , Michelangelo L. Mangano , Alexander Mitov , Juan Rojo

Twelve measurements of inclusive cross sections of W$^\pm$ and Z boson production, performed in proton-proton collisions at centre-of-mass energies of 7 and 8 TeV, are compared with perturbative quantum chromodynamics calculations at…

High Energy Physics - Experiment · Physics 2020-06-09 CMS Collaboration