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Related papers: Small $x$ Contributions to the Structure Function …

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The behavior of the gluon distribution function and the reduced cross section considered from the proton structure function and its derivatives at low values of $x$. These behaviors studied and compared with the experimental data. These…

High Energy Physics - Phenomenology · Physics 2020-11-17 B. Rezaei , G. R. Boroun

We give predictions for the ratio RQ(x,Q2)=FLQ(x,Q2)/F2Q(x,Q2) at small values of Bjorken variable x in the first three orders of perturbation theory. We show an approximate x-independence of RQ(x,Q2) at low x and non-large Q2 values (Q2 <…

High Energy Physics - Phenomenology · Physics 2023-03-29 N. A. Abdulov , A. V. Kotikov , A. V. Lipatov

We study the perturbative QCD description of the HERA measurements of $F_2 (x, Q^2)$ using a gluon distribution that is obtained from an evolution incorporating angular ordering of the gluon emissions, and which embodies both GLAP and BFKL…

High Energy Physics - Phenomenology · Physics 2009-10-28 J. Kwiecinski , A. D. Martin , P. J. Sutton

We analyze the uncertainties induced by different definitions of the momentum fraction $z$ in the application of gluon to heavy quarkonium fragmentation function. We numerically calculate the initial $g \to J / \psi$ fragmentation functions…

High Energy Physics - Phenomenology · Physics 2008-11-26 W. Qi , C. F. Qiao , J. X. Wang

We present a detailed description of the Q^2 and x dependence of the structure functions F2 and FL as extracted from the Deep Inelastic Scattering data at HERA in the small Bjorken x region. Making use of a collinearly-improved BFKL…

High Energy Physics - Phenomenology · Physics 2013-04-10 Martin Hentschinski , Agustin Sabio Vera , Clara Salas

The longitudinal structure function is considered at the next-to-leading order approximation using the expansion method, as defined by M.B.Gay Ducati and P.B.Goncalves [Phys.Lett.B {\bf390}, 401 (1997)] and further developed by Jingxuan…

High Energy Physics - Phenomenology · Physics 2025-04-04 G. R. Boroun , Yanbing Cai

A reanalysis of the model for the longitudinal structure function $F_L (x,Q^2)$ at low $x$ and low $Q^2$ was undertaken, in view of the advent of the EIC. The model is based on the photon-gluon fusion mechanism suitably extrapolated to the…

High Energy Physics - Phenomenology · Physics 2022-04-20 B. Badelek , A. M. Stasto

A measurement of the derivative (d ln F_2 / d lnx)_(Q^2)= -lambda(x,Q^2) of the proton structure function F_2 is presented in the low x domain of deeply inelastic positron-proton scattering. For 5*10^(-5)<=x<=0.01 and Q^2>=1.5 GeV^2,…

High Energy Physics - Experiment · Physics 2010-03-25 H1 Collaboration , C. Adloff

Nucleon resonance contributions to the inclusive proton $F_2$ and $F_L$ structure functions are computed from resonance electroexcitation amplitudes in the mass range up to 1.75 GeV extracted from CLAS exclusive meson electroproduction…

High Energy Physics - Phenomenology · Physics 2021-08-11 A. N. Hiller Blin , W. Melnitchouk , V. I. Mokeev , V. D. Burkert , V. V. Chesnokov , A. Pilloni , A. P. Szczepaniak

We calculate the cross section of a pion diffraction dissociation in two jets with large transverse momenta originating from a hard gluon exchange between the pion constituents. To the leading logarithmic accuracy (in energy), the…

High Energy Physics - Phenomenology · Physics 2009-11-07 V. M. Braun , D. Yu. Ivanov , A. Schaefer , L. Szymanowski

We calculate the impact factor coupling a virtual photon to a gluon via a massive quark-antiquark pair at LL order, but with the imposition of the correct gluon kinematics. Exact analytical results are presented in triple Mellin space with…

High Energy Physics - Phenomenology · Physics 2008-11-26 C. D. White , R. Peschanski , R. S. Thorne

We calculate the gluon structure function of a color dipole in a new approach evaluating the matrix elements of SU(2) gluon field operators separated along a direction close to the light cone. As vacuum state in the pure glue sector, we use…

High Energy Physics - Phenomenology · Physics 2010-02-04 D. Grünewald , E. -M. Ilgenfritz , H. J. Pirner

Explicit expressions for the non-singlet and singlet structure functions g_1 at the small $x$-region are obtained. They include the total resummation of double-logarithmic contributions and accounting for the running QCD coupling effects.…

High Energy Physics - Phenomenology · Physics 2016-09-06 B. I. Ermolaev , M. Greco , S. I. Troyan

This talks examines the effect of angular ordering on the small-x evolution of the unintegrated gluon distribution, and discusses the characteristic function for the CCFM equation.

High Energy Physics - Phenomenology · Physics 2009-10-30 G. P. Salam

Fragmentation is the dominant production mechanism for heavy hadronic bound states with large transverse momentum. We numerically calculate the initial $g\rightarrow H(Q\bar{Q})$ fragmentation functions (FFs) using the nonrelativistic QCD…

High Energy Physics - Phenomenology · Physics 2016-10-19 S. Mohammad Moosavi Nejad , Delpasand Mahdi

The contribution of the nonperturbative quark-gluon interaction induced by the instantons to $g_1^p(x,Q^2)$ and $F_2^p(x,Q^2)$ structure functions is estimated. It is shown that nontrivial $Q^2$ dependence of the instanton contribution to…

High Energy Physics - Phenomenology · Physics 2007-05-23 N. I. Kochelev

We perform a perturbative QCD analysis of the nucleon's Pauli form factor $F_2(Q^2)$ in the asymptotically large $Q^2$ limit. We find that the leading contribution to $F_2(Q^2)$ has a $1/Q^6$ power behavior, consistent with the well-known…

High Energy Physics - Phenomenology · Physics 2009-11-07 Andrei V. Belitsky , Xiangdong Ji , Feng Yuan

We consider the interaction of the partonic fluctuation of a scalar ``photon'' with an external color field to calculate the leading and next-to-leading order gluon distribution of the proton following the work done by…

High Energy Physics - Phenomenology · Physics 2009-11-10 H. -J. Pirner , A. I. Shoshi , G. Soyez

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

We calculate the gluon structure function of a color dipole in near-light-cone SU(2) lattice QCD as a function of $x_B$. The quark and antiquark are external non-dynamical degrees of freedom which act as sources of the gluon string…

High Energy Physics - Theory · Physics 2013-05-29 D. Grünewald , E. -M. Ilgenfritz , H. J. Pirner