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Related papers: Large N_f calculations in deep inelastic scatterin…

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The heavy quark effects in deep--inelastic scattering in the asymptotic regime $Q^2 \gg m^2$ can be described by heavy flavor operator matrix elements. Complete analytic expressions for these objects are currently known to ${\sf NLO}$. We…

High Energy Physics - Phenomenology · Physics 2009-06-25 I. Bierenbaum , J. Blümlein , S. Klein

We calculate the $O(\alpha_s^3)$ heavy flavor contributions to the Wilson coefficients of the structure function $F_2(x,Q^2)$ and the massive operator matrix elements (OMEs) for the twist--2 operators of unpolarized deeply inelastic…

High Energy Physics - Phenomenology · Physics 2009-07-22 Isabella Bierenbaum , Johannes Blümlein , Sebastian Klein

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 investigate the power-suppressed corrections to fragmentation functions in flavour-singlet deep inelastic lepton scattering, to complement the previous results for the non-singlet contribution. Our method is a dispersive approach based…

High Energy Physics - Phenomenology · Physics 2009-10-31 Graham Smye

The anomalous dimensions of four-quark operators $(\bar q_i q_j)_{V-A} (\bar q_k q_l)_{V-A}$ are calculated in the large $N_f$ limit. As expected, the result is a convergent series without renormalon ambiguities. Using the approximation of…

High Energy Physics - Phenomenology · Physics 2007-05-23 N. Pott

We present results on the calculation of the polarized 2- and 3-loop anomalous dimensions in a massive computation of the associated operator matrix element. We also discuss the treatment of $\gamma_5$ and derive results in the M-scheme.10

In this article we consider n gluon color ordered, planar amplitudes in N=4 super Yang Mills at strong 't Hooft coupling. These amplitudes are approximated by classical surfaces in AdS_5 space. We compute the value of the amplitude for a…

High Energy Physics - Theory · Physics 2010-04-06 Luis F. Alday , Juan Maldacena

The behaviour of the quark coefficient functions in deep-inelastic scattering is investigated for large values of the Bjorken variable x. By combining results of soft-gluon resummation and fixed-order calculations, we determine the…

High Energy Physics - Phenomenology · Physics 2009-10-31 A. Vogt

We present results for the three-loop universal anomalous dimension of Wilson twist-2 operators in the N=4 Supersymmetric Yang-Mills model. These results are obtained by extracting the most complicated contributions from the three loop…

High Energy Physics - Theory · Physics 2016-09-06 A. V. Kotikov , L. N. Lipatov , A. I. Onishchenko , V. N. Velizhanin

A c++ implementation of the D_s-dimensional unitarity cut algorithm for the numerical evaluation of the virtual contribution to NLO QCD amplitudes is presented. The current version includes an arbitrary number of external gluons with…

High Energy Physics - Phenomenology · Physics 2008-12-17 A. Lazopoulos

We consider the n -> 0 limit of the DGLAP splitting function gamma_gg(a) at all orders in the strong coupling constant, a, by analysing the leading order large N_f form of the associated d-dimensional critical exponent. We show that for…

High Energy Physics - Phenomenology · Physics 2010-03-25 J. F. Bennett , J. A. Gracey

The resummation of soft gluon exchange for QCD hard scattering requires a matrix of anomalous dimensions. We compute this matrix directly for arbitrary 2 to n massless processes for the first time at two loops. Using color generator…

High Energy Physics - Phenomenology · Physics 2009-04-06 S. Mert Aybat , Lance J. Dixon , George Sterman

Recently it was shown that the scaling dimension of the operator $\phi^n$ in scale-invariant $d=3$ theory may be computed semiclassically, and this was verified to leading order (two loops) in perturbation theory at leading and subleading…

High Energy Physics - Theory · Physics 2025-06-03 I. Jack , D. R. T. Jones

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

A leading twist expansion in terms of bi-local operators is proposed for the structure functions of deeply inelastic scattering near the elastic limit $x \to 1$, which is also applicable to a range of other processes. Operators of…

High Energy Physics - Phenomenology · Physics 2014-11-17 R. Akhoury , M. G. Sotiropoulos , G. Sterman

We compute the non-planar contribution to the universal anomalous dimension of twist-two operators in N=4 supersymmetric Yang-Mills theory at four loops through Lorentz spin eighteen. Exploiting the results of this and our previous…

High Energy Physics - Theory · Physics 2021-06-30 B. A. Kniehl , V. N. Velizhanin

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

Using an analytical parameterization for the behavior of the x slope of the structure function F_2 at small x in perturbative QCD, at the leading twist approximation of the Wilson operator product expansion, and applying a flat initial…

High Energy Physics - Phenomenology · Physics 2014-11-17 A. V. Kotikov , G. Parente

The deep inelastic scattering data on the nucleon F_2 structure function, accumulated by BCDMS, SLAC and NMC collaborations in fixed-target experiments, are analyzed in the non-singlet approximation within the frameworks of both…

High Energy Physics - Phenomenology · Physics 2024-03-21 A. V. Kotikov , B. G. Shaikhatdenov , N. S. Korchagin , P. Zhang

We study the correlation function between one single-trace scalar operator and a circular Wilson loop in the $4d$ $\mathcal{N}=2$ superconformal field theory with gauge group $SU(N)$ and matter transforming in the symmetric and…

High Energy Physics - Theory · Physics 2023-06-19 Alessandro Pini , Paolo Vallarino
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