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Related papers: Polarized Gluon Distribution Delta g(x) in the Pro…

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We obtain the gluon parton distribution functions (PDFs) in the proton within the extended light-front holographic QCD framework, where the proton couples with the spin-two Pomeron in Anti-de Sitter space, together with constraints imposed…

High Energy Physics - Phenomenology · Physics 2023-03-29 Bheemsehan Gurjar , Chandan Mondal , Dipankar Chakrabarti

The gluon polarization $\Delta G$ in a nucleon can be defined in a gauge invariant way as the integral over the Ioffe-time distribution of polarized gluons. We argue that for sufficiently regular polarized gluon distributions $\Delta G$ is…

High Energy Physics - Phenomenology · Physics 2009-10-30 L. Mankiewicz , G. Piller , A. Saalfeld

In the context of the so-called valon model, we calculate $\frac{\delta g}{g}$ and show that although it is small and compatible with the measured values, the gluon contribution to the spin of nucleon can be sizable. The smallness of…

High Energy Physics - Phenomenology · Physics 2014-11-21 Abolfazl Shahveh , Fatemeh Taghavi-Shahri , Firooz Arash

Recently the possible existence of negative gluon helicity, $\Delta g$, has been observed to be compatible with existing empirical constraints, including from jet production in polarized proton-proton collisions at RHIC, and lattice QCD…

High Energy Physics - Phenomenology · Physics 2024-03-15 N. T. Hunt-Smith , C. Cocuzza , W. Melnitchouk , N. Sato , A. W Thomas , M. J. White

The recent high precision SMC data on polarized $\mu p$ scatterings have again confirmed that very little of the proton spin is carried by quarks. To unravel the mystery of the proton spin structure, it is quite important to know the…

High Energy Physics - Phenomenology · Physics 2009-10-28 T. Morii , S. Tanaka , T. Yamanishi

A recent global QCD analysis of jet production and other polarized scattering data has found the presence of negative solutions for the gluon helicity distribution in the proton, $\Delta g$, along with the traditional $\Delta g > 0$…

High Energy Physics - Phenomenology · Physics 2026-05-04 R. M. Whitehill , Yiyu Zhou , N. Sato , W. Melnitchouk

We make a first crude direct estimate of the net gluon polarization in the proton, DeltaG, combining data on the asymmetries in high-p_T hadron production from the HERMES, SMC and COMPASS collaborations. Although these data sample a…

High Energy Physics - Phenomenology · Physics 2009-09-11 John Ellis , Marek Karliner

Using the recently proposed $gg\eta'$ effective vertex, we investigate the production of $\eta'$ from gluon fusion in polarized pp collisions. We show that by measuring $A_{LL}$ in $\eta'$ production, one can extract the polarized gluon…

High Energy Physics - Phenomenology · Physics 2009-11-07 Sangyong Jeon , Jamal Jalilian-Marian

Little information is known about the polarization of gluons inside a longitudinally polarized proton. I report on the sensitivity of photoproduction experiments to it. Both jet and heavy quark production are considered.

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

In order to get information about the polarized gluon distribution in a proton, we studied the electroproduction of \psi' in polarized electron and polarized proton collisions in the framework of the NRQCD factorization approach. The value…

High Energy Physics - Phenomenology · Physics 2011-03-23 Kazutaka Sudoh , Han-Wen Huang , Toshiyuki Morii

We determine the polarized gluon distribution \Delta g(x) by a global analysis using current DIS and \pi^0 asymmetry data. The \pi^0 data from RHIC-Spin experiments provide a strong constraint on \Delta g(x), so that its uncertainty is…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. Hirai , S. Kumano , N. Saito

We develop simple analytic representations of the polarized quark and gluon distributions in the nucleon at low $Q^2$ which incorporate general constraints obtained from the requirements of color coherence of gluon couplings at $x \sim 0$…

High Energy Physics - Phenomenology · Physics 2009-09-25 Stanley J. Brodsky , Matthias Burkardt , Ivan Schmidt

We combine heavy-quark renormalization group arguments with our understanding of the nucleon's wavefunction to deduce a bound on the gluon polarization Delta g in the proton. The bound is consistent with the values extracted from spin…

High Energy Physics - Phenomenology · Physics 2011-10-25 Steven D. Bass , Andrew Casey , Anthony W. Thomas

We present a determination of the gluon polarization Delta G/G in the nucleon, based on the helicity asymmetry of quasi-real photoproduction events, Q^2<1(GeV/c)^2, with a pair of large transverse-momentum hadrons in the final state. The…

High Energy Physics - Experiment · Physics 2008-11-26 COMPASS Collaboration , E. S. Ageev

The distribution of the spin of the nucleon among its constituents can be parametrized in the form of polarized parton distribution functions for quarks and gluons. Using all available data on the polarized structure function $g_1(x,Q^2)$,…

High Energy Physics - Phenomenology · Physics 2014-11-17 T. Gehrmann , W. J. Stirling

In QCD the gauge-invariant gluon polarization Delta G in a nucleon can be defined either in a non-local way as the integral over the Ioffe-time distribution of polarized gluons, or in light-cone gauge as the forward matrix element of the…

High Energy Physics - Phenomenology · Physics 2011-09-13 A. Saalfeld , G. Piller , L. Mankiewicz

We investigate the polarized gluon distribution \Delta g(x) by a global analysis of current DIS data and the \pi^0 data from RHIC-Spin experiments. The \pi^0 data provide a strong constraint on \Delta g(x), so that its uncertainty is…

High Energy Physics - Phenomenology · Physics 2017-08-23 M. Hirai , S. Kumano , N. Saito

We derive the Leading-Order master equation to extract the polarized gluon distribution G(x;Q^2) = x \deltag(x;Q^2) from polarized proton structure function, g1p(x;Q^2). By using a Laplace-transform technique, we solve the master equation…

High Energy Physics - Phenomenology · Physics 2011-03-14 F. Taghavi-Shahri , A. Mirjalili , M. M. Yazdanpanah

We investigate the possibility to draw conclusions on the sign of the spin-dependent gluon distribution, $\Delta G(x, Q^2)$, from existing polarized DIS data. The spin-dependent parton distributions $\Delta u_v, \Delta d_v, \Delta {\bar u},…

High Energy Physics - Phenomenology · Physics 2007-05-23 W. -D. Nowak , A. V. Sidorov , M. V. Tokarev

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 simulation…

High Energy Physics - Phenomenology · Physics 2009-10-28 J. Feltesse , F. Kunne , E. Mirkes
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