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Related papers: Small-x behaviour of the polarized structure funct…

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We present new improved parton distributions for the photon. We fit {\bf all} available data on the photon structure function, $F^{\gamma}_{2}(x,Q^2)$, with $Q^2\ge 3$ GeV$^2$, in order to determine the quark distributions. We also pay…

High Energy Physics - Phenomenology · Physics 2011-07-19 L. E. Gordon , J. K. Storrow

We investigate the evolution of parton densities at small values of the momentum fraction, x, by including resummed anomalous dimensions in the renormalization group equations. The resummation takes into account the leading-logarithmic…

High Energy Physics - Phenomenology · Physics 2016-09-01 R. K. Ellis , F. Hautmann , B. R. Webber

We analyse the available data on the polarized asymmetries $A_1$ for proton, neutron and deuteron targets. We use a homogeneous and updated set of unpolarized structure functions to derive $g_1$ from $A_1$, and we accurately correct for the…

High Energy Physics - Phenomenology · Physics 2009-10-22 G. Altarelli , P. Nason , G. Ridolfi

We investigate the nucleon and pion gluon distribution functions in the framework of holographic QCD, focusing on the small Bjorken x region. Based on an approximate relation, the gluon distributions are extracted from structure functions…

High Energy Physics - Phenomenology · Physics 2020-06-24 Akira Watanabe , Takahiro Sawada , Mei Huang

We illustrate geometric scaling for the photon-proton cross section with a very simple saturation model. We describe the proton structure function F2 at small x in a wide kinematical range with an elementary functional form and a small…

High Energy Physics - Phenomenology · Physics 2009-11-07 S. Munier

We evaluate the unintegrated gluon distribution of the proton starting from a parametrization of the color dipole cross section including DGLAP evolution and saturation effects. To this end, we perform the Fourier-Bessel transform of…

High Energy Physics - Phenomenology · Physics 2022-12-14 Agnieszka Łuszczak , Marta Łuszczak , Wolfgang Schäfer

We calculate the perturbative parts of the structure functions $F_2^c$ and $F_L^c$ for a gluon target having nonzero transverse momentum squared at order $\alpha_s$. The results of the double convolution (with respect to the Bjorken…

High Energy Physics - Phenomenology · Physics 2011-09-13 A. V. Kotikov , A. V. Lipatov , G. Parente , N. P. Zotov

The small-$x$ contributions to the Bjorken sum rule within unified picture $ln^2x+$LO DGLAP for different input parametrisations $g_1^{NS}(x,Q_0^2)$ are presented. Theoretical predictions for $\int_{0}^{0.003} g_1^{NS}(x,Q^2=10) dx$ are…

High Energy Physics - Phenomenology · Physics 2014-11-18 D. Kotlorz , A. Kotlorz

The $F_{2}$ structure functions of the inelastic lepton-hadron scattering is calculated in the case of non-zero intermediate gluon-quarks self-energy $M_{gq}^{2}$ and quasielastic limit. It is shown that in the quasielastic limit the…

High Energy Physics - Phenomenology · Physics 2007-05-23 Ya. D. Krivenko-Emetov

We perform an extensive study of the scale dependence of flavor-singlet contributions to the structure function g_2(x,Q^2) in polarized deep-inelastic scattering. We find that the mixing between quark-antiquark-gluon and three-gluon twist-3…

High Energy Physics - Phenomenology · Physics 2014-11-17 V. M. Braun , G. P. Korchemsky , A. N. Manashov

The hadronic structure function of the photon F_2^gamma is measured as a function of Bjorken x and of the factorisation scale Q^2 using data taken by the OPAL detector at LEP. Previous OPAL measurements of the x dependence of F_2^gamma are…

High Energy Physics - Experiment · Physics 2017-08-23 R. J. Taylor

The $F_{2}$, $F_{G}$, $R=F_{L}/F_{T}$ proton structure functions are derived in the QCD dipole picture of BFKL dynamics. We get a three parameter fit describing the 1994 H1 proton structure function $F_{2}$ data in the low $x$, moderate…

High Energy Physics - Phenomenology · Physics 2009-10-30 Ch. Royon

The behavior of the gluon distribution of the proton in the low-$x$, low-$Q^2$ domain of deep inelastic electron-proton scattering (DIS) is being investigated. By considering two-gluon exchange as the dominant interaction in the low-$x$,…

High Energy Physics - Phenomenology · Physics 2026-02-24 G. R. Boroun , M. Kuroda , Dieter Schildknecht

We present approximations of varying degree of sophistication to the integral equations for the (gluon) structure functions of a hadron (``the partonic flux factor'') in a model valid in the Leading Log Approximation with a running coupling…

High Energy Physics - Phenomenology · Physics 2009-10-30 B. Andersson , G. Gustafson , H. Kharraziha

The interaction of the partonic fluctuation of the virtual photon in deep inelastic scattering with soft color fields describing the hadron is treated in an eikonal approximation. It is known that, in this approach, the small-x limit of the…

High Energy Physics - Phenomenology · Physics 2008-11-26 H. G. Dosch , A. Hebecker , A. Metz , H. J. Pirner

We determined the saturation exponent of the gluon distribution using the solution of the QCD nonlinear Dokshitzer-Gribov-Lipatov-Altarelli-parisi (NLDGLAP) evolution equation at small $x$. The very small $x$ behavior of the gluon…

High Energy Physics - Phenomenology · Physics 2014-02-06 G. R. Boroun

We present a consistent calculation of the structure functions within a light-front constituent quark model of the nucleon. Relativistic effects and the relevance of the covariance constraints are analyzed for both polarized and unpolarized…

High Energy Physics - Phenomenology · Physics 2009-10-31 P. Faccioli , M. Traini , V. Vento

Three pomerons are known to couple via the gluon loop and interactions of this kind which are responsible for high-mass diffraction are described in terms of the gluonic structure function of the QCD pomeron. We show that the triple-pomeron…

High Energy Physics - Phenomenology · Physics 2009-11-10 V. R. Zoller

Polarized photon structure can be studied in the future polarized $e^{+}e^{-}$ colliding-beam experiments. We investigate the spin-dependent structure function of the virtual photon $g_1^{\gamma}(x,Q^2,P^2)$, in perturbative QCD for…

High Energy Physics - Phenomenology · Physics 2016-08-25 Ken Sasaki , Tsuneo Uematsu

We investigate the internal structure of the pion, including the contributions from one dynamical gluon, using the basis light-front quantization (BLFQ) approach. By solving a light-front QCD Hamiltonian with a three-dimensional confining…

High Energy Physics - Phenomenology · Physics 2025-09-29 Jiangshan Lan , Kaiyu Fu , Satvir Kaur , Zhimin Zhu , Chandan Mondal , Xingbo Zhao , James P. Vary