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Related papers: Perturbative Gluon Shadowing in Heavy Nuclei

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The transverse momentum spectra of hadrons is calculated from the unintegrated gluon distribution (UGD) within the $k_T$-factorization framework at small $x$. Starting from $pp$ collisions, the modification caused by the nuclear medium is…

High Energy Physics - Phenomenology · Physics 2021-03-03 L. S. Moriggi , G. M. Peccini , M. V. T. Machado

We re-examine the predictions of a two-phase model of shadowing in nuclear deep-inelastic scattering in light of new NMC data on the x, A and Q**2 dependence of the ratios of structure functions. The model, which combines vector meson…

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

We extend the QCD Parton Model analysis using a factorized nuclear structure model incorporating individual nucleons and pairs of correlated nucleons. Our analysis of high-energy data from lepton Deep-Inelastic Scattering, Drell-Yan and W/Z…

Unintegrated gluon densities in nuclei, dipole-nucleus cross-sections and quark densities are numerically investigated in the high-colour limit, with the scattering on a heavy nucleus exactly described by the sum of fan diagrams of BFKL…

High Energy Physics - Phenomenology · Physics 2009-01-07 N. Armesto , M. A. Braun

We discuss the inclusive dilepton cross section for proton (quark)-nucleus collisions at high energies in the very forward rapidity region. Starting from the calculation in the quasi-classical approximation, we include low-x evolution…

High Energy Physics - Phenomenology · Physics 2009-11-10 R. Baier , A. H. Mueller , D. Schiff

The BFKL and the unified angular-ordered equations are solved to determine the gluon distribution at small $x$. The impact of kinematic constraints is investigated. Predictions are made for observables sensitive to the gluon at small $x$.…

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

While the phenomenon of gluon nuclear shadowing at small $x$ has been getting confirmation in QCD analyses of various LHC measurements involving heavy nuclei, it has not been possible so far to establish experimentally the number of target…

High Energy Physics - Phenomenology · Physics 2022-12-21 V. Guzey , M. Rinaldi , S. Scopetta , M. Strikman , M. Viviani

We numerically study for the first time the nonlinear GLR-MQ evolution equations for nuclear parton distribution function (nPDFs) to next-to-leading order accuracy and quantify the impact of gluon recombination at small $x$. Using the…

High Energy Physics - Phenomenology · Physics 2023-03-15 J. Rausch , V. Guzey , M. Klasen

Gluon distributions in real and virtual photons are calculated using evolution equations in the NLO approximation. The quark distributions in the photon determined on the basis of the QCD sum rule approach in ref.[1] are taken as an input.…

High Energy Physics - Phenomenology · Physics 2019-08-17 B. L. Ioffe , A. Oganesian

We investigate shadowing effects in deep-inelastic scattering from nuclei at small values $x<0.1$ of the Bjorken variable. Unifying aspects of generalized vector meson dominance and color transparency we first develop a model for…

High Energy Physics - Phenomenology · Physics 2015-06-25 G. Piller , W. Ratzka , W. Weise

Nuclear modification of the structure function $F_3$ is investigated. Although it could be estimated in the medium and large $x$ regions from the nuclear structure function $F_2^A$, it is essentially unknown at small $x$. The nuclear…

High Energy Physics - Phenomenology · Physics 2016-09-01 R. Kobayashi , S. Kumano , M. Miyama

We study the distribution of gluons in transverse space in the nucleon at moderately small x (~10^{-2}). At large transverse distances (impact parameters) the gluon density is generated by the 'pion cloud' of the nucleon, and can be…

High Energy Physics - Phenomenology · Physics 2009-11-10 M. Strikman , C. Weiss

We explain how Regge theory and perturbative evolution may be made compatible at small x. The result not only gives striking support to the two-pomeron description of small-x behaviour, but gives a rather clean test of perturbative QCD…

High Energy Physics - Phenomenology · Physics 2014-11-17 A Donnachie , P V Landshoff

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

Saturation and geometrical scaling (GS) of gluon distributions are a consequence of the non-linear evolution equations of QCD. We argue that in pp GS holds for the inelastic cross-section rather than for the multiplicity distributions. We…

High Energy Physics - Phenomenology · Physics 2016-07-15 Michal Praszalowicz

We examine the low Bjorken $x$ gluon distribution in nuclei in the asymptotic region.

High Energy Physics - Phenomenology · Physics 2014-11-17 F. Cano , S. Liuti

This paper contains three parts relating to the nucleon spin structure in a simple picture of the nucleon: (i) The polarized gluon distribution in the proton is dynamically predicted starting from a low scale by using a nonlinear QCD…

High Energy Physics - Phenomenology · Physics 2015-10-14 Wei Zhu , Jianhong Ruan

We study evolution of colour gluon states in isolated QCD jet at the non-perturbative stage. Fluctuations of gluons are less than those for coherent states under specific conditions. This fact suggests that there gluon squeezed states can…

High Energy Physics - Phenomenology · Physics 2009-11-07 V. I. Kuvshinov , V. A. Shaparau , V. V. Marmysh

In coordinate space, quark and gluon distributions of the nucleon are defined as correlation functions involving two field operators separated by a light-cone distance $y^+ = 2l$. We study the nuclear modifications of these distributions.…

High Energy Physics - Phenomenology · Physics 2009-10-31 M. Vänttinen , G. Piller , L. Mankiewicz , W. Weise , K. J. Eskola

We discuss the behaviour of R(pA), the ratio of the unintegrated gluon distribution of a nucleus over the unintegrated gluon distribution of a proton scaled up by A^{1/3}, at high energy and fixed coupling. We show that R(pA) exhibits a…

High Energy Physics - Phenomenology · Physics 2007-09-03 Misha Kozlov , Arif I. Shoshi , Bo-Wen Xiao