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Related papers: Angular ordering and small-x structure functions

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We discuss the quantitative consequences of the resummation of the small-x contributions to the anomalous dimensions beyond next-to-leading order in alpha_s and up to next order in ln(1/x) (NLx) in a framework based on the renormalization…

High Energy Physics - Phenomenology · Physics 2007-05-23 J. Blümlein , V. Ravindran , W. L. van Neerven , A. Vogt

We review small $x$ contributions to perturbative evolution equations for parton distributions, and their resummation. We emphasize in particular the resummation technique recently developed in order to deal with the apparent instability of…

High Energy Physics - Phenomenology · Physics 2007-05-23 Guido Altarelli , Richard D. Ball , Stefano Forte

We discuss the angular dependence of the recently proposed transverse momentum dependent quark and gluon diffractive parton distributions at small-$x$. We introduce the difractive versions of the Sivers function and the elliptic gluon…

High Energy Physics - Phenomenology · Physics 2024-03-29 Yoshitaka Hatta , Feng Yuan

The impact of the resummation of leading small-$x$ terms in the anomalous dimensions is briefly summarized for the evolution of non--singlet and singlet polarized structure functions.

High Energy Physics - Phenomenology · Physics 2007-05-23 J. Blümlein , A. Vogt

In this paper we derive an integral equation for the evolution of unintegrated (longitudinally) polarized quark and gluon parton distributions. The conventional CCFM framework is extended at small x in order to incorporate the QCD…

High Energy Physics - Phenomenology · Physics 2009-11-07 Jan Kwiecinski , Martin Maul

We present the numerical solution of the leading order QCD evolution equation for the orbital angular momentum distributions of quarks and gluons and discuss its implications for the nucleon spin sum rule. We observe that at small-$x$, the…

High Energy Physics - Phenomenology · Physics 2018-04-11 Yoshitaka Hatta , Dong-Jing Yang

We review and discuss the use of TMD, or "unintegrated", gluon distributions in the domain of small-x physics. The definitions employed, and the hazards of the naive applications of the TMD factorization and the associated gluon…

High Energy Physics - Phenomenology · Physics 2015-05-30 Emil Avsar

We solve a unified integral equation to obtain the $x, Q_T$ and $Q$ dependence of the gluon distribution of a proton in the small $x$ regime; where $x$ and $Q_T$ are the longitudinal momentum fraction and the transverse momentum of the…

High Energy Physics - Phenomenology · Physics 2014-11-17 J. Kwiecinski , A. D. Martin , P. J. Sutton

Recent studies of two-dimensional poly-disperse disc systems revealed a coordinated self-organisation of cell stresses and shapes, with certain distributions collapsing onto a master form for many processes, size distributions, friction…

Soft Condensed Matter · Physics 2025-08-26 Dominik Krengel , Haoran Jiang , Takashi Matsushima , Raphael Blumenfeld

Recent developments of the small $x$ CCFM evolution are described, including improvements of the splitting function. The resulting unintegrated gluon densities are used for predictions of hadronic final state measurements like jet…

High Energy Physics - Phenomenology · Physics 2011-01-25 Hannes Jung

We present a phenomenological study of the small-x behaviour of gluon distribution function $G(x,Q^2)$ at next-to-leading order (NLO) and next-to-next-to-leading order(NNLO) in light of the nonlinear Gribov-Ryskin-Levin-Mueller-Qiu…

High Energy Physics - Phenomenology · Physics 2019-01-23 M. Lalung , P. Phukan , J. K. Sarma

A systematic study is performed of the impact of the various resummed small-$x$ contributions to the anomalous dimensions and coefficient functions on the evolution of unpolarized structure functions in deep-inelastic scattering. The proton…

High Energy Physics - Phenomenology · Physics 2009-10-30 J. Blümlein , A. Vogt

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

A next-to-next-to-leading order (NNLO) QCD calculation of gluon distribution function at small-x is presented. The gluon distribution function is explored analytically in the DGLAP approach by a Taylor expansion at small x as two first…

High Energy Physics - Phenomenology · Physics 2018-08-10 Mayuri Devee , J. K. Sarma

A survey is given of recent developments on the resummed small-$x$ evolution, in a framework based on the renormalization group equation, of non--singlet and singlet structure functions in both unpolarized and polarized deep--inelastic…

High Energy Physics - Phenomenology · Physics 2015-06-25 J. Blümlein , S. Riemersma , A. Vogt

We revisit the problem of the small Bjorken-$x$ asymptotics of the quark and gluon orbital angular momentum (OAM) distributions in the proton utilizing the revised formalism for small-$x$ helicity evolution derived recently in a paper by…

High Energy Physics - Phenomenology · Physics 2023-07-20 Brandon Manley

The system of CCFM equations for unintegrated parton distributions in a photon is considered in the single loop approximation. We include quarks and non-singular parts of the splitting functions in the corresponding evolution equations. We…

High Energy Physics - Phenomenology · Physics 2014-11-17 A. Gawron , J. Kwiecinski

We study the small-$x$ behaviour of the polarized photon structure function $F_3^{\ga}$, measuring the gluon transversity distribution, in the leading logarithmic approximation of perturbative QCD. There are two contributions, both arising…

High Energy Physics - Phenomenology · Physics 2014-11-17 B. Ermolaev , R. Kirschner , L. Szymanowski

We discuss the small $x$ behaviour of the spin dependent structure function $g_1$. We find a contribution from the exchange of two non-perturbative gluons which behaves as $\sim ( 2 \ln {1 \over x} -1)$.

High Energy Physics - Phenomenology · Physics 2009-10-28 S D Bass , P V Landshoff

An approximated solution for gluon distribution from DGLAP evolution equations with NLO splitting function in the small-$x$ limit is presented. We first obtain the simplified forms of LO and NLO splitting functions in the small-$x$ limit.…

High Energy Physics - Phenomenology · Physics 2024-01-29 Jingxuan Chen , Xiaopeng Wang , Yanbing Cai , Xurong Chen , Qian Wang