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Related papers: Perturbative QCD Evolution and Color Dipole Pictur…

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We report a semi-analytical approach for the solution of the nonlinear Gribov-Levin-Ryskin-Mueller-Qiu (GLR-MQ) evolution equation for sea quark distribution and investigate the effect of gluon shadowing on the small-x and moderate-Q^2…

High Energy Physics - Phenomenology · Physics 2018-08-09 Mayuri Devee

The drastic rise of the proton structure function F_2(x,Q^2) when the Bj\"orken variable x decreases, seen at HERA for a large span of Q^2, negative values for the 4-momentum transfer, may be damped when Q^2 increases beyond several…

High Energy Physics - Phenomenology · Physics 2014-11-17 P. Desgrolard , A. Lengyel , E. Martynov

Low-Q^2 photons do not resolve partons in the proton, which gives problems when applying the deep inelastic scattering formalism, such as an unphysical, negative gluon density extracted from data. Considering instead hadronic fluctuations…

High Energy Physics - Phenomenology · Physics 2008-11-26 Johan Alwall , Gunnar Ingelman

The energy evolution of the fluctuating proton structure is studied by solving the JIMWLK renormalization group equation. The initial condition at moderate $x$ is obtained by fitting the charm reduced cross section data from HERA, requiring…

High Energy Physics - Phenomenology · Physics 2019-02-20 Heikki Mäntysaari , Björn Schenke

The differential cross section of exclusive diffractive vector meson production in electron proton collisions carries important information on the geometric structure of the proton. More specifically, the coherent cross section as a…

High Energy Physics - Phenomenology · Physics 2016-09-07 Heikki Mäntysaari , Björn Schenke

The ``asymmetric'' matrix element <p-r|G...G|p> that appears in the pQCD description of hard diffractive electroproduction does not coincide with that defining the gluon distribution function f_g(x). I outline a pQCD formalism based on a…

High Energy Physics - Phenomenology · Physics 2016-09-06 A. V. Radyushkin

We construct a simple two-phase model of the nucleon structure functions valid for both small and large Q^2 and in the broad range of Bjorken x. The model incorporates hadron dominance at small x and Q^2 and parton model at large Q^2. The…

High Energy Physics - Phenomenology · Physics 2015-06-25 A. Szczurek , V. Uleshchenko

We demonstrate that the global properties of the ``rapidity gap'' events, observed at HERA, can be understood based on electron-gluon scattering as the underlying partonic process. Using the measured inclusive structure function $F_2$ to…

High Energy Physics - Phenomenology · Physics 2009-02-20 W. Buchmuller , A. Hebecker

We investigate the unpolarized virtual photon structure functions $F_2^gamma(x,Q^2,P^2)$ and $F_L^gamma(x,Q^2,P^2)$ in perturbative QCD for the kinematical region $Lambda^2 ll P^2 ll Q^2$, where $-Q^2(-P^2)$ is the mass squared of the probe…

High Energy Physics - Phenomenology · Physics 2008-11-26 T. Ueda , K. Sasaki , T. Uematsu

We report an evaluation of subleading eigenvalues and eigenfunctions of the BFKL equation in the color dipole representation with a running gauge coupling. We present an expansion of the small-$x$ proton structure function $F_{2p}(x,Q^2)$…

High Energy Physics - Phenomenology · Physics 2009-10-30 Vladimir R. Zoller

In the framework of Anisotropic Chromo Dynamics, a non-perturbative model of QCD based on magnetic condensation in the vacuum, we develope a picture of the Pomeron. Within this model we are able to calculate the diffractive contribution to…

High Energy Physics - Phenomenology · Physics 2009-10-28 L. Dick , V. Karapetian , R. Barni , G. Preparata

The long standing mystery of smallness of diffractive dissociation of hadrons to large effective masses (the Pomeron-proton cross section is only 2 mb) witnesses that the gluonic clouds of valence quarks are so small (r_0=0.3fm) that soft…

High Energy Physics - Phenomenology · Physics 2009-10-31 B. Z. Kopeliovich

We derive an evolution equation describing the high energy behavior of the cross section for the single diffractive dissociation in deep inelastic scattering on a hadron or a nucleus. The evolution equation resums multiple BFKL pomeron…

High Energy Physics - Phenomenology · Physics 2009-10-31 Yuri V. Kovchegov , Eugene Levin

In QCD hard scattering cross sections, the color content of the underlying hard scattering evolves with a factorization scale. This evolution is controlled by an anomalous dimension matrix, specific to each hard-scattering reaction.…

High Energy Physics - Phenomenology · Physics 2014-11-17 Nikolaos Kidonakis , Gianluca Oderda , George Sterman

We examine both analytically and numerically the validity of factorization for the double dipole scattering amplitude T^{(2)} which appears on the right hand side of the BK--JIMWLK equation. We demonstrate that, if one uses a dilute object…

High Energy Physics - Phenomenology · Physics 2008-11-26 Emil Avsar , Yoshitaka Hatta

The conventional approach to perturbative evolution is illegal because the expansion in powers of $\alpha_s$ of the the DGLAP splitting matrix ${\bf P(z,\alpha_s)}$ breaks down at small $z$. The small-$x$ data for the proton structure…

High Energy Physics - Phenomenology · Physics 2007-05-23 P V Landshoff

The results of a measurement of the proton structure function F_2(x,Q^2)and the virtual photon-proton cross section are reported for momentum transfers squared Q^2 between 0.35 GeV^2 and 3.5 GeV^2 and for Bjorken-x values down to 6 10^{-6}…

High Energy Physics - Experiment · Physics 2008-11-26 C. Adloff

We continue our studies of possible generalization of the Color Glass Condensate (CGC) effective theory of high energy QCD to include the high $p_t$ (or equivalently large $x$) QCD dynamics as proposed in [JJM-elastic]. Here we consider…

High Energy Physics - Phenomenology · Physics 2019-02-06 Jamal Jalilian-Marian

We have measured the spin structure functions $g_1$ and $g_2$ of $^3$He in a double-spin experiment by inclusively scattering polarized electrons at energies ranging from 0.862 to 5.07 GeV off a polarized $^3$He target at a 15.5$^{\circ}$…

High Energy Physics - Experiment · Physics 2012-08-27 010 Collaboration , M. Amarian , L. Auerbach , T. Averett , J. Berthot

By means of the 10-resonance unitary and analytic model of nucleon electromagnetic structure it is demonstrated that the JLab proton polarization data on the ratio $\mu_p G_{Ep}(Q^2)/G_{Mp}(Q^2)$ are consistent with all form factor…

High Energy Physics - Phenomenology · Physics 2007-08-02 A. Z. Dubnickova , S. Dubnicka