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Related papers: Saturation and geometrical scaling in small system…

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Progresses towards the calculation and the understanding of NLO/NLL contributions to Deep Inelastic Scattering at low x with gluon saturation are being reviewed.

High Energy Physics - Phenomenology · Physics 2015-06-03 Guillaume Beuf

The CCFM equation and its extended form with a quadratic term (KGBJS equation) are solved with fixed and running coupling constant. The solution of the KGBJS equation is compared to gluon densities resulting from the CCFM and BK equations.…

High Energy Physics - Phenomenology · Physics 2013-11-13 Krzysztof Kutak , Dawid Toton

It has been found that the gluon density inside the proton grows rapidly at small momentum fractions. Quantum Chromodynamics (QCD) predicts that this growth can be regulated by nonlinear effects, ultimately leading to gluon saturation.…

High Energy Physics - Phenomenology · Physics 2025-09-03 Kiera Cassar , Zhen Wang , Xiaoxuan Chu , Elke-Caroline Aschenauer

We show that geometrical scaling exhibited by the $p_{\rm T}$ spectra measured by the CMS collaboration at the LHC is substantially improved if the exponent $\lambda$ of the saturation scale depends on $p_{\rm T}$. This dependence is shown…

High Energy Physics - Phenomenology · Physics 2015-03-17 Michal Praszalowicz

We investigate the energy dependence of the photo-production cross-section of vector mesons $J/\Psi$ and $\Upsilon$, measured by both HERA experiments H1 and ZEUS in electron-proton collisions and by LHC experiments ALICE, CMS and LHCb in…

High Energy Physics - Phenomenology · Physics 2019-08-12 Martin Hentschinski , Krzysztof Kutak

We show that geometric scaling is satisfied to good accuracy in the forward region of d+Au collisions at RHIC. Scaling violations do show up, however, at mid-rapidity, and the anomalous dimension of the small-x gluon distribution evolves to…

High Energy Physics - Phenomenology · Physics 2014-11-18 Adrian Dumitru , Arata Hayashigaki , Jamal Jalilian-Marian

We investigate the recently proposed nonlinear equation for the unintegrated gluon distribution function which includes the subleading effects at small $x$. We obtained numerically the solution to this equation in $(x,k)$ space, and also…

High Energy Physics - Phenomenology · Physics 2008-11-26 K. Kutak , A. M. Stasto

We study the small-$x$ evolution equation for the gluon generalized parton distribution (GPD) $E_g$ of the nucleon. It is shown that $E_g$ at vanishing skewness exhibits the Regge behavior identical to the BFKL Pomeron, despite its…

High Energy Physics - Phenomenology · Physics 2022-12-22 Yoshitaka Hatta , Jian Zhou

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

The upcoming p+Pb run at the LHC will probe the nuclear gluon distribution at very small Bjorken x (from $x \sim 10^{-4}$ at mid-rapidity down to $x \sim 10^{-6}$ in the proton fragmentation region) and will allow to test approaches based…

High Energy Physics - Phenomenology · Physics 2012-10-23 Adrian Dumitru , Dmitri E. Kharzeev , Eugene M. Levin , Yasushi Nara

I review the physical and mathematical foundations for the theoretical description of the hadron wavefunction at small $x$ as a Colour Glass Condensate. In this context, I discuss the phenomenon of gluon saturation and some of its…

High Energy Physics - Phenomenology · Physics 2011-01-25 Edmond Iancu

We consider a novel mechanism for J/Psi production in nuclear collisions arising due to the high density of gluons. We calculate the resulting J/Psi production cross section as a function of rapidity and centrality. We evaluate the nuclear…

High Energy Physics - Phenomenology · Physics 2009-06-16 Dmitri Kharzeev , Eugene Levin , Marzia Nardi , Kirill Tuchin

We calculate the cross section of a single inclusive gluon production in deep inelastic scattering at very high energies in the saturation regime, where the parton densities inside hadrons and nuclei are large and the evolution of structure…

High Energy Physics - Phenomenology · Physics 2009-11-07 Yuri V. Kovchegov , Kirill Tuchin

We numerically study the effects of high gluon density at small x on the evolution of gluon distribution function in both hadrons and nuclei. Using a newly derived, Wilson renormalization group-based evolution equation which includes n to 1…

High Energy Physics - Phenomenology · Physics 2014-11-17 Jamal Jalilian-Marian , Xin-Nian Wang

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

In this paper we show that the intuitive guess that the geometric scaling behaviour should be violated in the case of the running QCD coupling, turns out to be correct. The scattering amplitude of the dipole with the size $r$ depends on new…

High Energy Physics - Phenomenology · Physics 2015-05-28 Bastian Diaz Saez , Eugene Levin

We present a detailed numerical investigation of semi-inclusive forward di-hadron production in proton-nucleus collisions employing the Color Glass Condensate effective theory. We focus on the regime where di-hadrons are produced nearly…

High Energy Physics - Phenomenology · Physics 2025-12-29 Paul Caucal , Zhong-Bo Kang , Piotr Korcyl , Farid Salazar , Björn Schenke , Tomasz Stebel , Raju Venugopalan , Wenbin Zhao

We present exploratory studies of the proton structure via two distinct kinds of gluon densities: the transverse-momentum dependent functions, whose evolution is determined by the CSS equation, and the unintegrated gluon distribution, whose…

High Energy Physics - Phenomenology · Physics 2022-10-18 Francesco Giovanni Celiberto

The exclusive vector meson production cross section is one of the most promising observables to probe the high energy regime of the QCD dynamics. In particular, the squared momentum transfer ($t$) distributions are an important source of…

High Energy Physics - Phenomenology · Physics 2017-04-05 V. P. Goncalves , F. S. Navarra , D. Spiering

I discuss the p_t distributions for high-multiplicity events originating from semi-classical variation of the gluon density of the proton.The multiplicity distribution measures the curvature of the effective action for the small-x gluon…

High Energy Physics - Phenomenology · Physics 2007-05-23 A. Dumitru