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Related papers: Fall and rise of the gluon splitting function

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This talk discusses the relative impact of running-coupling and other higher-order corrections on the small-x gluon-gluon splitting function. Comments are made on similarities with some aspects of the Balitsky-Kovchegov equation, which…

High Energy Physics - Phenomenology · Physics 2007-05-23 G. P. Salam

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 basic features of the gluon density predicted by a renormalisation group improved small-x equation which incorporates both the gluon splitting function at leading collinear level and the exact BFKL kernel at…

High Energy Physics - Phenomenology · Physics 2010-03-25 M. Ciafaloni , D. Colferai , G. P. Salam , A. M. Stasto

Evolution of gluon distribution function from Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) evolution equation in next-to-leading order (NLO) at low-x is presented assuming the Regge behaviour of quarks and gluons at this limit. We…

High Energy Physics - Phenomenology · Physics 2010-03-25 U. Jamil , J. K. Sarma

We have computed the even-N moments N =< 20 of the gluon-gluon splitting function P_{gg} at the fourth order of perturbative QCD via the renormalization of off-shell operator matrix elements. Our results, derived analytically for a general…

High Energy Physics - Phenomenology · Physics 2024-10-11 G. Falcioni , F. Herzog , S. Moch , A. Pelloni , A. Vogt

We present the next-to-next-to-leading order (NNLO) contributions to the main splitting functions for the evolution of longitudinally polarized parton densities of hadrons in perturbative QCD. The quark-quark and gluon-quark splitting…

High Energy Physics - Phenomenology · Physics 2015-06-22 S. Moch , J. A. M. Vermaseren , A. Vogt

We review the status of the calculation of the time-like splitting functions for the evolution of fragmentation functions to the next-to-next-to-leading order in perturbative QCD. By employing relations between space-like and time-like…

High Energy Physics - Phenomenology · Physics 2008-07-03 S. Moch , A. Vogt

We compute the effect of soft-gluon resummation, at the next-to-leading-logarithmic level, in the hadroproduction cross-section for heavy flavours. Applications to top, bottom and charm total cross-sections are discussed. We find in general…

High Energy Physics - Phenomenology · Physics 2008-11-26 R. Bonciani , S. Catani , M. L. Mangano , P. Nason

We discuss perturbative evolution of the polarized structure function g_1 in the (x,Q^2) plane, with special regard to the small-x region. We determine g_1 in terms of polarized quark and gluon distributions using coefficient functions to…

High Energy Physics - Phenomenology · Physics 2009-10-28 R. D. Ball , S. Forte , G. Ridolfi

We present preliminary results for fits of parton distribution functions (PDFs) which include the resummation of small-$x$ logarithms at NLLx accuracy, performed in the NNPDF framework. We observe an improvement in the description of DIS…

High Energy Physics - Phenomenology · Physics 2017-07-07 Luca Rottoli , Marco Bonvini

We study the next-to-next-to-leading order (NNLO) evolution of flavour non-singlet quark densities and structure functions in massless perturbative QCD. Present information on the corresponding three-loop splitting functions is used to…

High Energy Physics - Phenomenology · Physics 2008-11-26 W. L. van Neerven , A. Vogt

The review of the nucleon spin structure functions problems is presented. The perturbative QCD predictions for the small x behaviour of the nucleon spin structure functions are discussed. The role of the resummation of the ln^2 1/x terms is…

High Energy Physics - Phenomenology · Physics 2007-05-23 Dorota Kotlorz

We compute the next-to-next-to-leading order (NNLO) contributions to the splitting functions governing the evolution of the unpolarized flavour-singlet parton densities in perturbative QCD. The exact expressions are presented in both…

High Energy Physics - Phenomenology · Physics 2010-04-05 A. Vogt , S. Moch , J. A. M. Vermaseren

We are investigating the behavior of the fragmentation function of a gluon, denoted as $ D_{g}(x,\mu^2)$, where $\mu$ represents the observable scale. This function is derived from the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP)…

High Energy Physics - Phenomenology · Physics 2025-09-25 H. S. Nakhaei , G. R. Boroun

We define a general scheme for the evolution of fragmentation functions which resums soft gluon logarithms in a manner consistent with fixed order evolution. We present an explicit example of our approach in which double logarithms are…

High Energy Physics - Phenomenology · Physics 2017-08-23 S. Albino

I discuss the effectiveness of soft-gluon resummations in describing higher-order corrections. I present a comparison of recent resummation approaches and their relative successes in approximating complete NNLO corrections. I also discuss…

High Energy Physics - Phenomenology · Physics 2023-02-21 Nikolaos Kidonakis

We present the calculation at next-to-leading order (NLO) in alpha_s of the fragmentation function of a gluon into heavy quarkonium in the color-octet spin-singlet S-wave channel. To calculate the real NLO corrections, we adapt a…

High Energy Physics - Phenomenology · Physics 2019-02-20 Pierre Artoisenet , Eric Braaten

In this work we have solved the nonlinear GLR-MQ evolution equation upto next-to-leading order (NLO) by considering NLO terms of the gluon-gluon splitting functions and running coupling constant $\alpha_s(Q^2)$. Here, we have incorporated a…

High Energy Physics - Phenomenology · Physics 2018-01-22 M. Lalung , P. Phukan , J. K. Sarma

We define a general scheme for the evolution of fragmentation functions which resums both soft gluon logarithms and mass singularities in a consistent manner and to any order, and requires no additional theoretical assumptions. Using the…

High Energy Physics - Phenomenology · Physics 2010-03-25 S. Albino , B. A. Kniehl , G. Kramer , W. Ochs

An alternative equation, resumming of the $\ln^2 1/x$ terms for the polarized nonsinglet structure function $g_1^{NS}$ at small $x$ is presented. Construction of the GLAP-like formula for the auxiliary function, corresponding to the…

High Energy Physics - Phenomenology · Physics 2011-03-17 Dorota Kotlorz , Andrzej Kotlorz