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Related papers: New results on small-x resummation for splitting f…

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We present a method for the analytic solution of small $x$ structure functions. The essential small $x$ logarithms are summed to all orders in the anomalous dimensions and coefficient functions. Although we work at leading logarithmic…

High Energy Physics - Phenomenology · Physics 2010-03-25 J. R. Forshaw R. G. Roberts R. S. Thorne

The explicit expressions for the non-singlet DIS structure function g_1 at small $x$ are obtained by resumming the leading logarithmic contributions. The role played by the fits for the initial parton densities currently used in the DGLAP…

High Energy Physics - Phenomenology · Physics 2009-11-11 B. I. Ermolaev , M. Greco , S. I. Troyan

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 analyze the iterative structure of unfactorized partonic structure functions in the large-x limit, and derive all-order expressions for the leading-logarithmic off-diagonal splitting functions P_gq and P_qg and the corresponding…

High Energy Physics - Phenomenology · Physics 2014-11-21 A. Vogt

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

We have studied the recently completed analytic all-N expressions for the four-loop anomalous dimensions corresponding to the next-to-next-to-next-to-leading order splitting functions for the non-singlet quark distribution in perturbative…

High Energy Physics - Phenomenology · Physics 2026-05-06 S. Moch , A. Vogt

I review recent results by Fadin,Lipatov and collaborators and by our group,leading to the almost complete calculation of the next-to-leading BFKL kernel,of its eigenvalues,and of the resummed gluon anomalous dimension. Qualitative…

High Energy Physics - Phenomenology · Physics 2007-05-23 Marcello Ciafaloni

We provide a method for the all order computation of small x contributions at the leading logarithmic level to cross-sections which are differential in rapidity. The method is based on a generalization to rapidity distributions of the high…

High Energy Physics - Phenomenology · Physics 2011-02-15 Fabrizio Caola , Stefano Forte , Simone Marzani

An approach which unifies the Double Logarithmic Approximation at small x and the leading order DGLAP evolution of fragmentation functions at large x is presented. This approach reproduces exactly the Modified Leading Logarithm…

High Energy Physics - Phenomenology · Physics 2011-04-11 S. Albino , B. A. Kniehl , G. Kramer , W. Ochs

We review recent progress in the development of an approach valid to any order which unifies the fixed-order DGLAP evolution of fragmentation functions at large x with soft-gluon logarithmic resummation at small x. At leading order, this…

High Energy Physics - Phenomenology · Physics 2008-11-26 B. A. Kniehl

The double logarithmic terms $\alpha_{s} \ln^{2}x $ are important to predict precisely the small $x$ behavior of the spin structure function $g_{1}$. We numerically analyze the evolution of the flavor non-singlet $g_{1}$ including the…

High Energy Physics - Phenomenology · Physics 2007-05-23 Yuichiro Kiyo , Jiro Kodaira , Hiroshi Tochimura

We study the splitting functions for the evolution of fragmentation distributions and the coefficient functions for single-hadron production in semi-inclusive electron-positron annihilation in massless perturbative QCD for small values of…

High Energy Physics - Phenomenology · Physics 2015-06-05 C. -H. Kom , A. Vogt , K. Yeats

The off-diagonal parton-scattering channels $g+\gamma^*$ and $q+\phi^*$ in deep-inelastic scattering are power-suppressed near threshold $x\to 1$. We address the next-to-leading power (NLP) resummation of large double logarithms of $1-x$ to…

High Energy Physics - Phenomenology · Physics 2020-12-02 Martin Beneke , Mathias Garny , Sebastian Jaskiewicz , Robert Szafron , Leonardo Vernazza , Jian Wang

We construct an anomalous dimension for small x evolution which goes beyond standard fixed order perturbative evolution by including resummed small x logarithms deduced from the leading order BFKL equation with running coupling.…

High Energy Physics - Phenomenology · Physics 2008-11-26 Guido Altarelli , Richard D. Ball , Stefano Forte

Fits to the final combined HERA deep-inelastic scattering cross-section data within the conventional DGLAP framework of QCD have shown some tension at low $x$ and low $Q^2$. A resolution of this tension incorporating $\ln(1/x)$-resummation…

Total resummation of double- and single- logarithms of x contributing to the spin-dependent structure function g_1 ensures its steep rise at small $x$. In the asymptotic limit x ->0, the resummation leads to the Regge behavior of g_1 and…

High Energy Physics - Phenomenology · Physics 2007-05-23 B. I. Ermolaev , M. Greco , S. I. Troyan

We present a small x resummation for the GLAP anomalous dimension and its corresponding dual BFKL kernel, which includes all the available perturbative information and nonperturbative constraints. Specifically, it includes all the…

High Energy Physics - Phenomenology · Physics 2010-03-25 Guido Altarelli , Richard D. Ball , Stefano Forte

We perform a threshold resummation calculation for the associated production of gluinos and gauginos at the LHC to the next-to-leading logarithmic accuracy. Analytical results are presented for the process-dependent soft anomalous dimension…

High Energy Physics - Phenomenology · Physics 2017-01-24 B. Fuks , M. Klasen , M. Rothering

We extend our previous results on small-x resummation in the pure Yang--Mills theory to full QCD with nf quark flavours, with a resummed two-by-two matrix of resummed quark and gluon splitting functions. We also construct the corresponding…

High Energy Physics - Phenomenology · Physics 2008-11-26 Guido Altarelli , Richard D. Ball , Stefano Forte

We present a systematic formalism for the derivation of the kernel of the BFKL equation from that of the GLAP equation and conversely to any given order, with full inclusion of the running of the coupling. The running coupling is treated as…

High Energy Physics - Phenomenology · Physics 2010-03-25 Richard D. Ball , Stefano Forte