English
Related papers

Related papers: Measuring the Gluon Helicity Difference Distributi…

200 papers

We use perturbative QCD, beyond the leading $\ln Q^2$ approximation, to show how measurements of diffractive $J/\psi$ production at HERA can provide a sensitive probe of the gluon density of the proton at small values of Bjorken $x$. We…

High Energy Physics - Phenomenology · Physics 2008-02-03 M. G. Ryskin , R. G. Roberts , A. D. Martin , E. M. Levin

We examine carefully bottomonia hadroproduction in proton colliders, especially focusing on the LHC, as a way of probing the gluon density in protons. To this end we develop some previous work, getting quantitative predictions and…

High Energy Physics - Phenomenology · Physics 2008-11-26 J. L. Domenech-Garret , M. A. Sanchis-Lozano , S. Wolf

We show that linearly polarized gluons inside unpolarized hadrons can be directly probed in jet or heavy quark pair production in electron-hadron collisions. We discuss the simplest cos (2 phi) asymmetries and estimate their maximal value,…

High Energy Physics - Phenomenology · Physics 2011-04-05 Daniel Boer , Stanley J. Brodsky , Piet J. Mulders , Cristian Pisano

We consider the possibility of a direct determination of the polarized gluon density in the proton using charm production with polarized beams at HERA. We study total cross sections and distributions at leading order using different…

High Energy Physics - Phenomenology · Physics 2011-07-19 S. Frixione , G. Ridolfi

Results of our next-to-leading order analytic calculation for longitudinally polarized photoproduction of heavy quarks are presented. Certain differential cross sections and the corresponding asymmetries are computed for energy ranges…

High Energy Physics - Phenomenology · Physics 2017-08-23 Z. V. Merebashvili , A. P. Contogouris , G. Grispos

A QCD analysis of jet production in deep-inelastic scattering is presented. The studies are based on recent measurements of jet cross sections in the H1 experiment at HERA which are directly sensitive to the gluon density in the proton. The…

High Energy Physics - Phenomenology · Physics 2019-08-14 Markus Wobisch

Transverse momentum dependent gluon distributions encode fundamental information on the structure of the proton. Here we show how they can be accessed in heavy quarkonium production in proton-proton collisions at the LHC. In particular,…

High Energy Physics - Phenomenology · Physics 2014-06-04 Cristian Pisano

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 study photoproduction of jets and heavy flavors in a polarized collider mode of HERA and in polarized $ep$ collisions at $\sqrt{S}\approx 30$ GeV. We examine the sensitivity of the cross sections and their asymmetries to the proton's…

High Energy Physics - Phenomenology · Physics 2011-07-19 M. Stratmann , W. Vogelsang

We study photoproduction of jets and single-inclusive hadrons in a polarized ep collider mode of HERA at sqrt(s)=300 GeV, examining the sensitivity of the cross sections and their asymmetries to the proton's polarized gluon distribution and…

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

I discuss few selected topics in heavy flavour photoproduction at HERA which require large integrated luminosity in order to be experimentally investigated. I present phenomenological predictions for bottom production. As a possible…

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

Two-jet production from the direct photon contribution at HERA is a sensitive measure of the small-$x$ gluon in the proton. We propose measurements of ratios of the jet cross-sections which will clearly distinguish between gluons with or…

High Energy Physics - Phenomenology · Physics 2008-11-26 JR Forshaw , RG Roberts

The measurement of the polarized gluon distribution function Delta G(x) from photon-gluon fusion processes in electron-proton deep inelastic scattering producing two jets has been investigated. The study is based on the MEPJET and PEPSI…

High Energy Physics - Phenomenology · Physics 2007-05-23 A. De Roeck , J. Feltesse , F. Kunne , M. Maul , E. Mirkes , G. Raedel , A. Schaefer , C. Y. Wu

The complete details of our calculation of the NLO QCD corrections to heavy flavor photo- and hadroproduction with longitudinally polarized initial states are presented. The main motivation for investigating these processes is the…

High Energy Physics - Phenomenology · Physics 2007-05-23 Ingo Bojak

We study photoproduction reactions in a polarized ep collider mode of HERA at sqrt(s)=298 GeV. We examine the sensitivity of the cross sections and their asymmetries to the proton's polarized gluon distribution and to the completely unknown…

High Energy Physics - Phenomenology · Physics 2007-05-23 M. Stratmann , W. Vogelsang

The STAR Collaboration is performing a wide range of measurements to determine the gluon helicity distribution in the proton. Gluon-gluon and quark-gluon scattering dominate jet production in proton-proton collisions at RHIC, so the…

High Energy Physics - Experiment · Physics 2019-08-13 Zilong Chang

Using updated gluon distributions from global fits to data, we investigate the sensitivity of direct photoproduction of heavy quarks and exclusive production of vector mesons to varying strength of gluon modifications. Implications of using…

Nuclear Theory · Physics 2015-03-19 Adeola Adeluyi , Carlos Bertulani

The production of jets in polarized proton collisions at STAR is dominated by quark-gluon and gluon-gluon scattering processes. The dijet longitudinal double-spin asymmetry $(A_{LL})$ is sensitive to the helicity distributions and may be…

High Energy Physics - Experiment · Physics 2016-08-05 Suvarna Ramachandran

The uncertainty in the calculation of many important new processes at the Tevatron and LHC is dominated by that concerning the gluon distribution function. We investigate the uncertainty in the gluon distribution of the proton by…

High Energy Physics - Phenomenology · Physics 2016-08-25 J. Huston , S. Kuhlmann , H. L. Lai , F. Olness , J. F. Owens , D. E. Soper , W. K. Tung

The polarization observables in phi photoproduction are suggested for probing the nucleon strangeness. Based on models for phi photoproduction, some double polarization observables are shown to be very sensitive to the strangeness content…

Nuclear Theory · Physics 2007-05-23 Yongseok Oh