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Related papers: Gluon Polarization in Nucleons

200 papers

The nucleon's tensor charges (isovector $g^v_T={\delta}u-{\delta}d$ and isoscalar $g^s_T={\delta}u+{\delta}d$) are calculated using the QCD sum rules in the presence of an external tensor field. In addition to the standard quark and gluon…

High Energy Physics - Phenomenology · Physics 2009-10-28 Hanxin He , Xiangdong Ji

The "g_{Delta N gamma}" coupling for the "Delta -> N gamma" decay is calculated in framework of the light cone QCD sum rules and is found to be g_{Delta N gamma} = (1.6 pm 0.2) GeV^(-1). Using this value of g_{Delta N gamma} we estimate the…

High Energy Physics - Phenomenology · Physics 2009-10-31 T. M. Aliev , M. Savci

We investigate the possibility of identifying an explicit pionic component of the nucleon through measurements of polarized $\Delta^{++}$ baryon fragments produced in deep-inelastic leptoproduction off polarized protons, which may help to…

High Energy Physics - Phenomenology · Physics 2008-11-26 W. Melnitchouk , A. W. Thomas

We outline an approach to calculate the transverse-momentum-dependent distribution of linearly polarized gluons inside an unpolarized hadron on the lattice with the help of large momentum effective theory. To achieve this purpose, we…

High Energy Physics - Phenomenology · Physics 2024-02-02 Shuai Zhao

We propose new Transverse Momentum Dependent (TMD) gluon densities in nuclei. Our method is based on a combination of the color dipole scattering formalism, within which we interpret the nuclear deep inelastic structure functions…

High Energy Physics - Phenomenology · Physics 2025-05-06 A. V. Lipatov , G. I. Lykasov , M. A. Malyshev

We study the available data in polarized e-p deep inelastic scattering to test two different solutions to the so called spin crisis: one of them based on the axial gluon anomaly and consistent with the Bjorken sum rule and another one,…

High Energy Physics - Phenomenology · Physics 2008-02-03 C. Bourrely , F. Buccella , O. Pisanti , P. Santorelli , J. Soffer

We perform explorative analyses of the 3D gluon content of the proton via a study of (un)polarized twist-2 gluon TMDs, calculated in a spectator model for the parent nucleon. Our approach encodes a flexible parametrization for the…

High Energy Physics - Phenomenology · Physics 2021-09-08 Francesco Giovanni Celiberto

Lattice quantum chromodynamics (QCD) calculations share a defining challenge by requiring a small finite range of spatial separation $z$ between quark/gluon bilinears for controllable power corrections in the perturbative QCD factorization,…

We consider the two-point function of nucleon current in nuclear matter and write a QCD sum rule to analyse the residue of the nucleon pole as a function of nuclear density. The nucleon self-energy needed for the sum rule is taken as input…

High Energy Physics - Phenomenology · Physics 2015-05-13 S. Mallik , Sourav Sarkar

The distribution of linearly polarized gluons inside a large nucleus is studied in the framework of the color glass condensate. We find that the Weizs\"acker-Williams distribution saturates the positivity bound at large transverse momenta…

High Energy Physics - Phenomenology · Physics 2015-05-28 Andreas Metz , Jian Zhou

We have extracted QCD matrix elements from our data on double polarized inelastic scattering of electrons on nuclei. We find the higher twist matrix element \tilde{d_2}, which arises strictly from quark- gluon interactions, to be…

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

We review recent progress in the description of unpolarized transverse-momentum-dependent (TMD) gluon distributions at small $x$ in the color glass condensate (CGC) effective theory. We discuss the origin of the non-universality of TMD…

High Energy Physics - Phenomenology · Physics 2018-07-27 Elena Petreska

We calculate the gluon momentum fraction of the nucleon using lattice quantum chromodynamics (QCD), with a nonperturbative renormalization technique based on the gradient flow. The gluon momentum fraction is determined on a single…

Charmonium sum rules are analyzed with the primary goal to obtain the restrictions on the value of dimension 4 gluon condensate. The moments M_n(Q^2) of the polarization operator of vector charm currents are calculated and compared with…

High Energy Physics - Phenomenology · Physics 2011-09-13 B. L. Ioffe , K. N. Zyablyuk

By using the background field method of QCD in a path integral approach, we derive the equation of motion for the classical chromofield and for the gluon in a system containing the gluon and the classical chromofield simultaneously. This…

High Energy Physics - Theory · Physics 2009-10-31 Qun Wang , Chung-Wen Kao , Gouranga C. Nayak , Horst Stoecker , Walter Greiner

The gluon condensate, $\langle \frac{\alpha_s}{\pi} G^2 \rangle$, i.e. the leading order power correction in the operator product expansion of current correlators in QCD at short distances, is determined from $e^+ e^-$ annihilation data in…

High Energy Physics - Phenomenology · Physics 2015-06-23 C. A. Dominguez , L. A. Hernandez , K. Schilcher

We compare a recent lattice determination of the nucleon distribution amplitudes with other approaches and models. We study the nucleon distribution amplitudes up to twist 6 in next-to leading conformal spin and we also investigate…

High Energy Physics - Phenomenology · Physics 2009-07-30 Alexander Lenz , Meinulf Göckeler , Thomas Kaltenbrunner , Nikolaus Warkentin

A QCD analysis of the world data on polarized deep inelastic scattering is presented in next--to--leading order, including the heavy flavor Wilson coefficient in leading order in the fixed flavor number scheme. New parameterizations are…

High Energy Physics - Phenomenology · Physics 2014-11-21 Johannes Blümlein , Helmut Böttcher

We recently proposed a QCD-Pomeron described by the exchange of two non-perturbative gluons characterized by a dynamically generated gluon mass. It is here shown that data on elastic scattering, exclusive $\rho$ production in deep inelastic…

High Energy Physics - Phenomenology · Physics 2011-07-19 M. B. Gay Ducati , F. Halzen , A. A. Natale