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Related papers: Four-Loop Non-Singlet Splitting Functions in the P…

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We consider the collinear limit of QCD amplitudes at one-loop order, and their factorization properties directly in colour space. These results apply to the multiple collinear limit of an arbitrary number of QCD partons, and are a basic…

High Energy Physics - Phenomenology · Physics 2009-11-10 German Rodrigo , Stefano Catani , Daniel de Florian , Werner Vogelsang

We consider non-planar one-loop anomalous dimensions in maximally supersymmetric Yang-Mills theory and its marginally deformed analogues. Using the basis of Bethe states, we compute matrix elements of the dilatation operator and find…

High Energy Physics - Theory · Physics 2020-12-02 Tristan McLoughlin , Raul Pereira , Anne Spiering

We update our approximate parametrizations of the three-loop splitting functions for the evolution of unpolarized parton densities in perturbative QCD. The new information taken into account is given by the additional Mellin moments…

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

We compute the four-loop $n_f$ contribution proportional to the quartic Casimir of the QCD cusp anomalous dimension as an expansion for small cusp angle $\phi$. This piece is gauge invariant, violates Casimir scaling, and first appears at…

High Energy Physics - Phenomenology · Physics 2017-10-17 Andrey Grozin , Johannes Henn , Maximilian Stahlhofen

We report on the first calculation of the structure function g_1 in polarised deep-inelastic scattering to the third order in massless perturbative QCD. The calculation follows the dispersive approach already used for the corresponding…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. Vogt , S. Moch , M. Rogal , J. A. M. Vermaseren

We explicitly compute the complete three-loop (O(g^4)) contribution to the four-point function of chiral primary current-like operators <(q)^2 q^2 (q)^2 q^2> in any finite N=2 SYM theory. The computation uses N=2 harmonic supergraphs in…

High Energy Physics - Theory · Physics 2009-10-31 B. Eden , C. Schubert , E. Sokatchev

We present numerical results for the nonplanar lightlike cusp and collinear anomalous dimension at four loops in ${\mathcal N} = 4$ SYM theory, which we infer from a calculation of the Sudakov form factor. The latter is expressed as a…

High Energy Physics - Theory · Physics 2017-12-21 Rutger H. Boels , Tobias Huber , Gang Yang

We present the first analytic results of N$^3$LO QCD corrections to the top-quark decay width. We focus on the dominant leading color contribution, which includes light-quark loops. At NNLO, this dominant contribution accounts for 95% of…

High Energy Physics - Phenomenology · Physics 2024-04-26 Long-Bin Chen , Hai Tao Li , Zhao Li , Jian Wang , Yefan Wang , Quan-feng Wu

We present splitting functions in the triple collinear limit at next-to-leading order. The computation was performed in the context of massless QCD+QED, considering only processes which include at least one photon. Through the comparison of…

High Energy Physics - Phenomenology · Physics 2014-11-21 German F. R. Sborlini , Daniel de Florian , German Rodrigo

We revisit the Next-to-Leading Order (two-loop) contributions to the Anomalous Dimensions of $\Delta F = 1$ four-quark operators in QCD. We devise a test for anomalous dimensions, that we regard as of general interest, and by means of which…

High Energy Physics - Phenomenology · Physics 2025-06-19 Pol Morell , Javier Virto

We calculate the small angle expansion of the four-loop QCD cusp anomalous dimension. As a byproduct of our calculation, we also obtain the four-loop anomalous dimension of the heavy-quark field in HQET. The validity of the calculational…

High Energy Physics - Phenomenology · Physics 2022-11-18 Andrey G. Grozin , Roman N. Lee , Andrey F. Pikelner

We present the four-loop remainder function for six-gluon scattering with maximal helicity violation in planar N=4 super-Yang-Mills theory, as an analytic function of three dual-conformal cross ratios. The function is constructed entirely…

High Energy Physics - Theory · Physics 2015-06-18 Lance J. Dixon , James M. Drummond , Claude Duhr , Jeffrey Pennington

In the framework of analytic approach to QCD, which has been recently intensively developed, the dependence of nonperturbative contributions in a running coupling of strong interaction on initial perturbative approximation to 3-loop order…

High Energy Physics - Phenomenology · Physics 2007-05-23 Aleksey I. Alekseev

We present the third-order contributions to the quark-gluon and gluon-quark timelike splitting functions for the evolution of fragmentation functions in perturbative QCD. These quantities have been derived by studying physical evolution…

High Energy Physics - Phenomenology · Physics 2015-05-28 A. A. Almasy , A. Vogt , S. Moch

These proceedings describe a computation of the large-$n_f$ terms contributing to the QCD splitting functions at the fourth order in the strong coupling constant $\alpha_s$. Using the FORCER package for the reduction of four-loop two-point…

High Energy Physics - Phenomenology · Physics 2017-09-04 Joshua Davies

We present the next-to-next-to-leading order (NNLO) calculation of quark quasi parton distribution functions (PDFs) in the large momentum effective theory. The nontrivial factorization at this order is established explicitly and the full…

High Energy Physics - Phenomenology · Physics 2021-02-24 Long-Bin Chen , Wei Wang , Ruilin Zhu

We have extended our previous computations of the even-N moments of the flavour-singlet four-loop splitting functions to N = 12 for the pure-singlet quark case and N = 10 for all other cases. These results, obtained using physical…

High Energy Physics - Phenomenology · Physics 2023-10-10 S. Moch , B. Ruijl , T. Ueda , J. Vermaseren , A. Vogt

We have computed semi-inclusive spin asymmetries for proton and deuteron targets including next to leading order (NLO) QCD corrections and contributions coming from the target fragmentation region. These corrections have been estimated…

High Energy Physics - Phenomenology · Physics 2016-08-15 D. de Florian , L. N. Epele , H. Fanchiotti , C. A. García Canal , S. Joffily , R. Sassot

We provide results for the one-loop triple-collinear color/spin-space splitting operators for the five possible processes, $q \to qq'\bar{q}'$, $q \to qq\bar{q}$, $q \to qgg$, $g \to gq\bar{q}$ and $g \to ggg$. The expressions are exact in…

High Energy Physics - Phenomenology · Physics 2022-07-11 Michał Czakon , Sebastian Sapeta

In this talk we examine how one-loop soft and collinear splitting functions occur in the calculation of next-to-next-to-leading order (NNLO) corrections to production rates, and we present the one-loop gluon soft and splitting functions,…

High Energy Physics - Phenomenology · Physics 2007-05-23 Zvi Bern , Vittorio Del Duca , William B. Kilgore , Carl R. Schmidt