Progress in the NNPDF global analysis and the impact of the legacy HERA combination

Abstract

The H1 and ZEUS collaborations have recently presented their final results for the combination of inclusive cross-section measurements taken during Run I and Run II at the HERA collider. In this contribution, following an overview of recent progress in the NNPDF framework, we quantify the impact of the legacy HERA dataset on the NNPDF3.0 analysis, finding that it has a very moderate effect in the global fit. On the other hand, we also find that a HERA-only fit using the legacy dataset leads to a rather more accurate determination of PDFs as compared to a fit including only the HERA-I data. We also explore the sensitivity of the fit with respect to kinematical cuts in the small-x and small-Q region, finding hints of a possible tension between data and theory.

9 pages, 8 figures, to appear in the proceedings of the European Physical Society Conference on High Energy Physics 2015 (EPS-HEP 2015), Vienna, Austria, 22nd to 29th of July 2015

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• Parton distributions from high-precision collider data
• PDF4LHC recommendations for LHC Run II
• Pinning down the large-x gluon with NNLO top-quark pair differential distributions
• Charm and beauty quark masses in the MMHT2014 global PDF analysis
• The impact of the final HERA combined data on PDFs obtained from a global fit
• Study of HERA ep Data at Low Q^2 and Low x_Bj and the Need for Higher-Twist Corrections to Standard pQCD Fits
• Weak boson production from D0 and LHCb in the NNPDF global analysis
• PDFs and Top Physics
• A QCD analysis of CMS inclusive differential Z production data at sqrt(s) = 8 TeV