A Global Fit to Scattering Data with NLL BFKL Resummations

Abstract

We calculate DIS-scheme splitting and coefficient functions for electromagnetic deep inelastic scattering with small x resummations, as given by the NLL BFKL equation with running coupling and approximate NLL resummed impact factors. The resummations are combined with a NLO fixed order expansion, and the improved quantities thus obtained are stable at small x and significantly suppressed with respect to LL results. These results are implemented in a global fit to DIS and related data, and the results compared to a NLO fixed order DIS-scheme fit and with a previous LL resummed fit. The NLL resummed fit quality is excellent, and constitutes a marked improvement over the purely fixed order approach. The input gluon, at Q_0^2=1GeV^2, obtained from the resummed fit is positive and slightly increasing as x-->0, in contrast to the result obtained at fixed order. A resummed prediction for the longitudinal structure function F_L is presented. It is positive definite and growing with energy at low x and Q^2, where the fixed order results show a significant perturbative instability.

52 pages, 27 figures

References in corpus (54)

• Big Bang Nucleosynthesis (in "The Review of Particle Properties" 2004)
• New Generation of Parton Distributions with Uncertainties from Global QCD Analysis
• Operator expansion for high-energy scattering
• Small-x F_2 Structure Function of a Nucleus Including Multiple Pomeron Exchanges
• Nonlinear Gluon Evolution in the Color Glass Condensate: I
• BFKL pomeron in the next-to-leading approximation
• Unitarity at small Bjorken x
• Energy Scale(s) and Next-to-leading BFKL Equation
• Deep-Inelastic Inclusive ep Scattering at Low x and a Determination of alpha_s
• Improved Measurement of the $\bar{d}/\bar{u}$ Asymmetry in the Nucleon Sea
• High-Energy Factorization and Small-X Deep Inelastic Scattering Beyond Leading Order
• Measurement of the proton and deuteron structure functions, F2p and F2d, and of the ratio sigma(L)/sigma(T)
• MRST2001: partons and alpha_S from precise deep inelastic scattering and Tevatron jet data
• The third-order QCD corrections to deep-inelastic scattering by photon exchange
• Measurement of the neutral current cross section and F2 structure function for deep inelastic e+p scattering at HERA
• A resummation of large sub-leading corrections at small x
• Charm electroproduction viewed in the variable-flavour number scheme versus fixed-order perturbation theory
• Renormalization Group Improved Small-x Equation
• Physical Gluons and High $E_T$ Jets
• Measurement and QCD Analysis of Neutral and Charged Current Cross Sections at HERA
• An Improved Determination of ${\alpha }_S$ From Neutrino-Nucleon Scattering
• Uncertainties of predictions from parton distributions. I: Theoretical errors
• A Variable-Flavour Number Scheme for NNLO
• Renormalisation group improved small-x Green's function
• Rates for Inclusive Deep-Inelastic Electroproduction of Charm Quarks at HERA
• Measurement of Neutral and Charged Current Cross Sections in Electron-Proton Collisions at High Q^2
• Measurement of D*+- production and the charm contribution to F_2 in deep inelastic scattering at HERA
• The BFKL Equation at Next-to-Leading Order and Beyond
• Accurate Measurement of F2d/F2p and Rd-Rp
• Irreducible part of the next-to-leading BFKL kernel
• Perturbatively Stable Resummed Small x Evolution Kernels
• Measurements of F_2 and xF_3(nu)-xF_3(nubar) from CCFR nu_mu-Fe and nubar_mu-Fe data in a physics model independent way
• Inclusive $D^0$ and $D^{\ast }\pm$ Production in Deep Inelastic $ep$ Collisions at HERA
• The Effect of Higher Order Corrections to the BFKL Equation on the Perturbative Pomeron
• NLO Corrections to the Photon Impact Factor: Combining Real and Virtual Corrections
• Measurement of the Inclusive Jet Cross Section in $\bar{p}p$ collisions at $\sqrt{s}=1.8$ TeV
• Inclusive Jet Production in pbar p Collisions
• Measurement of the lepton charge asymmetry in W-boson decays produced in p-pbar collisions
• The Running Coupling BFKL Anomalous Dimensions and Splitting Functions
• High-Q^2 neutral current cross sections in e^+p deep inelastic scattering at sqrt{s}=318 GeV
• Small-x Resummation and HERA Structure Function Data
• The Process γ^{*}_L+ q \to q\bar{q}g + q: Real Corrections to the Virtual Photon Impact Factor
• NLO Corrections to the γ* Impact Factor: First Numerical Results for the Real Corrections to γ*_L
• The (gamma^*-q\bar q)-Reggeon Vertex in Next-to-Leading Order QCD
• Measurement of high-Q^2 charged current cross sections in e^+p deep inelastic scattering at HERA
• Photon-Reggeon Interaction Vertices in the Nla
• On the Calculation of the NLO Virtual Photon Impact Factor
• Dimensional Regularisation and Factorisation Schemes in the BFKL Equation at Subleading Leve
• Minimal Subtraction vs. Physical Factorisation Schemes in Small-x QCD
• QCD dipole model and k_T factorization
• A Variable Flavour Number Scheme for Charged Current Heavy Flavour Structure Functions
• A Variable Flavour Number Scheme for Heavy Quark Production at Small x
• Comparison of NNLO DIS scheme splitting functions with results from exact gluon kinematics at small x
• The Virtual Photon-Gluon Impact Factor with Massive Quarks and Exact Gluon Kinematics

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• Parton distributions in the LHC era: MMHT 2014 PDFs
• Uncertainties on alpha_S in global PDF analyses and implications for predicted hadronic cross sections
• Parton distributions from LHC, HERA, Tevatron and fixed target data: MSHT20 PDFs
• AAMQS: A non-linear QCD analysis of new HERA data at small-x including heavy quarks
• The Structure of the Proton in the LHC Precision Era
• Parton distributions with small-x resummation: evidence for BFKL dynamics in HERA data
• Small x Resummation with Quarks: Deep-Inelastic Scattering
• Neutrino Telescopes as QCD Microscopes
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• Measurement of the Longitudinal Proton Structure Function at HERA
• Predictions for high energy neutrino cross-sections from the ZEUS global PDF fits
• Small-$x$ resummation from HELL
• A matrix formulation for small-x singlet evolution
• Exact kinematics in the small x evolution of the color dipole and gluon cascade
• Deviations from NLO QCD evolution in inclusive HERA data
• Hunting BFKL in semi-hard reactions at the LHC
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• Structure Functions
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• High-energy resummed distributions for the inclusive Higgs-plus-jet production at the LHC
• Double resummation for Higgs production
• A new simple PDF parametrization: improved description of the HERA data
• The Quark and Gluon Structure of the Proton
• Using HERA Data to Determine the Infrared Behaviour of the BFKL Amplitude
• BFKL at Next-to-Next-to-Leading Order
• High-energy emissions of light mesons plus heavy flavor at the LHC and the Forward Physics Facility
• Towards parton distribution functions with small-$x$ resummation: HELL 2.0
• Recent results on unintegrated parton distributions
• Ultraforward production of a charmed hadron plus a Higgs boson in unpolarized proton collisions
• Evidence for the Discrete Asymptotically-Free BFKL Pomeron from HERA Data
• F_L proton structure function from the unified DGLAP/BFKL approach
• Vector quarkonia at the LHC with JETHAD: A high-energy viewpoint
• Dynamical NNLO parton distributions and the perturbative stability of F_L(x,Q^2)
• Differential heavy quark pair production at small $x$
• Twist expansion of the nucleon structure functions, F2 and FL, in the DGLAP improved saturation model
• Exotic tetraquarks at the HL-LHC with JETHAD: A high-energy viewpoint
• The Green Function for the BFKL Pomeron and the Transition to DGLAP Evolution
• The Behaviour of the Green Function for the BFKL Pomeron with Running Coupling
• Four-loop splitting functions at small $x$
• On the different forms of the kinematical constraint in BFKL
• Aspects of High Energy Scattering
• Diffractive $J/\Psi$ photoproduction at large momentum transfer in coherent hadron - hadron interactions at CERN LHC
• Can we trust small x resummation?
• The SAGEX Review on Scattering Amplitudes, Chapter 12: Amplitudes and collider physics
• Small x resummation in collinear factorisation
• Triply Heavy $\Omega$ Baryons with JETHAD: A High-Energy Viewpoint
• Tetraquark-Jet Systems at the High-Luminosity LHC
• Structure functions from renormalization group improved small $x$ evolution
• Taming of preasymptotic small x evolution within resummation framework
• Dynamical parton distribution functions
• Analysis of HERA data with a PDF parametrization inspired by quantum statistical mechanics
• Collinear and TMD distributions with dynamical soft-gluon resolution scale
• An analysis of the longitudinal structure function at next-to-leading order approximation at small-$x$
• Summary of the HERA-LHC workshop