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Related papers: Parton Distributions in Nuclei at Small x

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I review recent theoretical results on polarized deep inelastic lepton nucleon scattering. Some specific issues, like $Q^2$ evolution of structure functions, the small $x$ behaviour, and the determination of polarized parton densities, are…

High Energy Physics - Phenomenology · Physics 2007-05-23 Giovanni Ridolfi

The role of gluons in the structure of the nucleon and light nuclei is investigated using lattice quantum chromodynamics (QCD) calculations. The first moment of the unpolarised gluon distribution is studied in nuclei up to atomic number…

High Energy Physics - Lattice · Physics 2017-12-06 Frank Winter , William Detmold , Arjun S. Gambhir , Kostas Orginos , Martin J. Savage , Phiala E. Shanahan , Michael L. Wagman

Using the NMC and E665 nuclear structure function ratios $F_2^A/F_2^D$ and $F_2^A/F_2^{C}$ from deep inelastic lepton-nucleus collisions, and the E772 Drell--Yan dilepton cross sections from proton-nucleus collisions, and incorporating…

High Energy Physics - Phenomenology · Physics 2014-11-17 K. J. Eskola , V. J. Kolhinen , P. V. Ruuskanen

We evaluate the shadowing effect in deeply virtual and real Compton scattering on nuclei in the framework of the color dipole model. We rely on the soft photon wave function derived in the instanton vacuum model, and employ the impact…

High Energy Physics - Phenomenology · Physics 2010-05-25 B. Z. Kopeliovich , Ivan Schmidt , M. Siddikov

The parton distributions in the proton are evaluated dynamically using a nonlinear QCD evolution equation - the DGLAP equation with twist-4 (the GLR-MQ-ZSR) corrections - starting from a low scale $\mu^2$, where the nucleon consists of…

High Energy Physics - Phenomenology · Physics 2014-09-11 Xurong Chen , Jianhong Ruan , Rong Wang , Pengming Zhang , Wei Zhu

New data from HERA experiment on deep inelastic scattering have been used to parametrize nucleon and Pomeron structure functions. Within the Gribov theory, the parameterizations were employed to calculate gluon shadowing for various heavy…

High Energy Physics - Phenomenology · Physics 2009-11-11 K. Tywoniuk , I. C. Arsene , L. Bravina , A. B. Kaidalov , E. Zabrodin

The distribution of the spin of the nucleon among its constituents can be parametrized in the form of polarized parton distribution functions for quarks and gluons. Using all available data on the polarized structure function $g_1(x,Q^2)$,…

High Energy Physics - Phenomenology · Physics 2014-11-17 T. Gehrmann , W. J. Stirling

We present and discuss the theory and phenomenology of the leading twist theory of nuclear shadowing which is based on the combination of the generalization of the Gribov-Glauber theory, QCD factorization theorems, and the HERA QCD analysis…

High Energy Physics - Phenomenology · Physics 2015-05-28 L. Frankfurt , V. Guzey , M. Strikman

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

The scale dependence of the ratios of parton distributions in a proton of a nucleus $A$ and in the free proton, $R_i^A(x,Q^2)=f_{i/A}(x,Q^2)/f_i(x,Q^2)$, is studied within the framework of the lowest order leading-twist DGLAP evolution. By…

High Energy Physics - Phenomenology · Physics 2014-11-17 K. J. Eskola , V. J. Kolhinen , C. A. Salgado

The gluon distribution in nuclei plays a pivotal role in understanding quantum chromodynamics (QCD) under extreme nuclear environments, yet remains poorly constrained compared to quark distributions. Coherent \jpsi photoproduction in…

High Energy Physics - Phenomenology · Physics 2025-02-14 Pengzhong Lu , Zebo Tang , Xin Wu , Wangmei Zha

Multiple scattering, induced radiative energy loss and modified fragmentation functions of a heavy quark in nuclear matter are studied within the framework of generalized factorization in perturbative QCD. Modified heavy quark fragmentation…

High Energy Physics - Phenomenology · Physics 2014-11-18 Ben-Wei Zhang , Enke Wang , Xin-Nian Wang

We introduce a nonperturbative interaction for light-cone fluctuations containing quarks and gluons. The $\bar qq$ interaction squeezes the transverse size of these fluctuations in the photon and one does not need to simulate this effect…

High Energy Physics - Phenomenology · Physics 2011-05-05 B. Z. Kopeliovich , A. Schaefer , A. V. Tarasov

We explore how nuclear modifications to the free nucleon structure functions (also known as shadowing) affect heavy quark production in collisions at different impact parameters. We assume that the nuclear modifications arise from a density…

Nuclear Theory · Physics 2014-11-18 V. Emel'yanov , A. Khodinov , S. R. Klein , R. Vogt

The uncertainty in the calculation of many important new processes at the Tevatron and LHC is dominated by that concerning the gluon distribution function. We investigate the uncertainty in the gluon distribution of the proton by…

High Energy Physics - Phenomenology · Physics 2016-08-25 J. Huston , S. Kuhlmann , H. L. Lai , F. Olness , J. F. Owens , D. E. Soper , W. K. Tung

We propose a new evolution equation for the gluon density relevant for the region of small $x_B$. It generalizes the GLR equation and allows deeper penetration in dense parton systems than the GLR equation does. This generalization consists…

High Energy Physics - Phenomenology · Physics 2009-09-25 E. Laenen , E. Levin

We use several diverse parameterizations of diffractive parton distributions, extracted in leading twist QCD analyses of the HERA diffractive deep inelastic scattering (DIS) data, to make predictions for leading twist nuclear shadowing of…

High Energy Physics - Phenomenology · Physics 2014-11-17 L. Frankfurt , V. Guzey , M. McDermott , M. Strikman

Determination of the nuclear parton distributions within the framework of perturbative QCD, the DGLAP equations in particular, is discussed. Scale and flavour dependent nuclear effects in the parton distributions are compared with the scale…

High Energy Physics - Phenomenology · Physics 2007-05-23 K. J. Eskola , H. Honkanen , V. J. Kolhinen , P. V. Ruuskanen , C. A. Salgado

The gluon distribution is dominated by the hard pomeron at small $x$ and all $Q^2$, with no soft-pomeron contribution. This describes well not only the DGLAP evolution of the hard-pomeron part of $F_2(x,Q^2)$, but also charm photoproduction…

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

We review recent theoretical developments in understanding the many-body perturbative QCD dynamics of strongly-interacting hard probes in dense nuclear matter. The relation between initial- and final-state parton scattering in nuclei and…

High Energy Physics - Phenomenology · Physics 2007-05-23 Ivan Vitev