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Related papers: Pinning down the Glue in the Proton

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We report global analysis results for polarized parton distribution functions in the nucleon. The optimum distributions are determined by using spin asymmetry data on polarized lepton scattering on proton, neutron, and deuteron. Their…

High Energy Physics - Phenomenology · Physics 2009-11-11 M. Hirai , S. Kumano , N. Saito

Inclusive jet production data are important for constraining the gluon distribution in the global QCD analysis of parton distribution functions. With the addition of recent CDF and D0 Run II jet data, we study a number of issues that play a…

High Energy Physics - Phenomenology · Physics 2010-04-23 Jon Pumplin , J. Huston , H. L. Lai , P. M. Nadolsky , Wu-Ki Tung , C. -P. Yuan

Parton distributions can be defined in terms of the entropy of entanglement between the spatial region probed by deep inelastic scattering (DIS) and the rest of the proton. For very small $x$, the proton becomes a maximally entangled state.…

High Energy Physics - Phenomenology · Physics 2021-09-08 Dmitri E. Kharzeev , Eugene Levin

We study the effect of absorptive corrections due to parton recombination on the parton distributions of the proton. A more precise version of the GLRMQ equations, which account for non-linear corrections to DGLAP evolution, is derived. An…

High Energy Physics - Phenomenology · Physics 2014-11-18 G. Watt , A. D. Martin , M. G. Ryskin

New measurements of dijet photoproduction at HERA provide information on the gluon density in the photon and on its quark densities at high x_gamma and high factorisation scales.

High Energy Physics - Experiment · Physics 2007-05-23 J. H. Vossebeld

The current uncertainty on the gluon density extracted from the global parton analysis is large in the kinematical range of small values of the Bjorken - $x$ variable and low values of the hard scale $Q^2$. An alternative to reduces this…

High Energy Physics - Phenomenology · Physics 2016-04-05 V. P. Goncalves , L. A. S. Martins , W. K. Sauter

We review recent experimental and theoretical developments in the study of the sea quark structure of the proton. In the light quark sector, we analyse the recent pp and pD Drell-Yan data from the E866/NuSea experiment at Fermilab, and…

High Energy Physics - Phenomenology · Physics 2007-05-23 W. Melnitchouk

The current status of global QCD analysis of parton distribution functions of the nucleon is reviewed. Recent progress made in determining various features of the parton structure of the nucleon, as well as outstanding open questions are…

High Energy Physics - Phenomenology · Physics 2009-09-29 Wu-Ki Tung

The contribution to the spin of the proton from the gluon helicity is starting to come into focus: for gluons carrying a large fraction $x$ of the proton momentum, evidence of positive gluon polarization has been observed, via measurements…

High Energy Physics - Experiment · Physics 2019-08-07 Christopher Dilks

The nuclear modification factor $R_{pA}(p_T)$ provides information on the small-$x$ gluon distribution of a nucleus at hadron colliders. Several experiments have recently measured the nuclear modification factor not only in minimum bias but…

High Energy Physics - Phenomenology · Physics 2018-05-09 Adrian Dumitru , Gary Kapilevich , Vladimir Skokov

Use of HERA jet production cross sections can extend our knowledge of the gluon parton distribution function and yield accurate measurements of $\alpha_s(M_Z)$ in addition to illustrating the running of $\alpha_s$ with scale.

High Energy Physics - Experiment · Physics 2017-08-23 A. M. Cooper-Sarkar

Electroproduction in deep inelastic scattering at HERA is studied in a model considering a finite sum of gluon ladders, associated with a truncation of the BFKL series. The approach contains the bare two gluon exchange and both one and two…

High Energy Physics - Phenomenology · Physics 2009-11-07 M. B. Gay Ducati , K. Kontros , A. Lengyel , M. V. T. Machado

Double-spin asymmetries for production of charged pions and kaons in semi-inclusive deep-inelastic muon scattering have been measured by the COMPASS experiment at CERN. The data, obtained by scattering a 160 GeV muon beam off a…

High Energy Physics - Experiment · Physics 2012-08-27 COMPASS Collaboration

Using a recent next-to-leading-order calculation of the photoproduction double differential cross section for heavy quarks, we study the possibility of extracting the gluon density of the proton from heavy-quark photoproduction data. We…

High Energy Physics - Phenomenology · Physics 2010-11-01 Stefano Frixione Michelangelo L. Mangano Paolo Nason , Giovanni Ridolfi

We extend the QCD Parton Model analysis using a factorized nuclear structure model incorporating individual nucleons and pairs of correlated nucleons. Our analysis of high-energy data from lepton Deep-Inelastic Scattering, Drell-Yan and W/Z…

In coordinate space, quark and gluon distributions of the nucleon are defined as correlation functions involving two field operators separated by a light-cone distance $y^+ = 2l$. We study the nuclear modifications of these distributions.…

High Energy Physics - Phenomenology · Physics 2009-10-31 M. Vänttinen , G. Piller , L. Mankiewicz , W. Weise , K. J. Eskola

We analyze the inclusive spectra of hadrons produced in $pp$ collisions at high energies in the mid-rapidity region within the soft QCD and perturbative QCD assuming the possible creation of the soft gluons at low intrinsic transverse…

High Energy Physics - Phenomenology · Physics 2015-05-30 G. I. Lykasov , V. A. Bednyakov , A. A. Grinyuk , M. Poghosyan , A. G. Dolbilov

A QCD analysis of the world data on polarized deep inelastic scattering is presented in leading and next-to-leading order. New parameterizations are derived for the quark and gluon distributions for the kinematic range $x \epsilon…

High Energy Physics - Phenomenology · Physics 2016-09-06 J. Blümlein , H. Böttcher

A feasibility study to extract the polarised gluon density from di-jet events at HERA in next-to-leading order is presented. It is shown that when taking next-to-leading order effects into account the asymmetries at HERA remain measurable…

High Energy Physics - Phenomenology · Physics 2007-05-23 G. Radel , A. De Roeck

The hard-gluonic contribution to the first moment of the polarized proton structure function $g_1^p(x)$ is dependent of the factorization convention chosen in defining the quark spin density and the hard cross section for photon-gluon…

High Energy Physics - Phenomenology · Physics 2009-10-28 Hai-Yang Cheng , Hung Hsiang Liu , Chung-Yi Wu