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Related papers: QCD cusp anomalous dimension: current status

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The 4-loop $C_F^3 T_F n_l$ and 5-loop $C_F^4 T_F n_l$ terms in the HQET field anomalous dimension $\gamma_h$ are calculated analytically (the 4-loop one agrees with the recent numerical result [arXiv:1801.08292]). The 4-loop $C_F^3 T_F n_l$…

High Energy Physics - Phenomenology · Physics 2018-08-01 Andrey Grozin

We review the current status of calculations of the HQET field anomalous dimension and the cusp anomalous dimension. In particular, we give the results at 4 loops for the quartic Casimir contribution, and for the full QED case, up to…

High Energy Physics - Phenomenology · Physics 2018-07-18 R. Brüser , A. G. Grozin , J. M. Henn , M. Stahlhofen

We compute the fermionic contributions to the cusp anomalous dimension in QCD at four loops as an expansion for small cusp angle. As a byproduct we also obtain the respective terms of the four-loop HQET wave function anomalous dimension.…

High Energy Physics - Phenomenology · Physics 2019-06-26 Robin Brüser , Andrey Grozin , Johannes M. Henn , Maximilian Stahlhofen

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 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 derive an analytic formula at three loops for the cusp anomalous dimension Gamma_cusp(phi) in N=4 super Yang-Mills. This is done by exploiting the relation of the latter to the Regge limit of massive amplitudes. We comment on the…

High Energy Physics - Theory · Physics 2015-06-04 Diego Correa , Johannes Henn , Juan Maldacena , Amit Sever

I present a general method for determining the massive cusp anomalous dimension in QCD to a very high degree of accuracy using its asymptotic behavior at small and large quark velocities. I show that the method works exceedingly well at two…

High Energy Physics - Phenomenology · Physics 2023-03-15 Nikolaos Kidonakis

We present the details of the analytic calculation of the three-loop angle-dependent cusp anomalous dimension in QCD and its supersymmetric extensions, including the maximally supersymmetric $\mathcal{N}=4$ super Yang-Mills theory. The…

High Energy Physics - Phenomenology · Physics 2016-02-17 Andrey Grozin , Johannes M. Henn , Gregory P. Korchemsky , Peter Marquard

I present analytical expressions for the cusp anomalous dimension in QCD through three loops in terms of elementary functions and ordinary polylogarithms. I observe interesting relations between the results at different loops and provide a…

High Energy Physics - Phenomenology · Physics 2016-05-25 Nikolaos Kidonakis

The angle-dependent cusp anomalous dimension governs divergences coming from soft gluon exchanges between heavy particles, such as top quarks. We focus on the matter-dependent contributions and compute the first truly non-planar terms. They…

High Energy Physics - Theory · Physics 2021-01-20 Robin Brüser , Christoph Dlapa , Johannes M. Henn , Kai Yan

We present the complete formula for the cusp anomalous dimension at four loops in QCD and in maximally supersymmetric Yang-Mills. In the latter theory it is given by \begin{equation} {\Gamma}^{\rm}_{\rm cusp}\Big|_{\alpha_s^4} = -\left(…

High Energy Physics - Theory · Physics 2019-11-25 Johannes M. Henn , Gregory P. Korchemsky , Bernhard Mistlberger

In this talk we present the result for the $n_f$ dependent piece of the three-loop cusp anomalous dimension in QCD. Remarkably, it is parametrized by the same simple functions appearing in analogous anomalous dimensions in ${\mathcal N}=4$…

High Energy Physics - Theory · Physics 2014-08-21 Andrey Grozin , Johannes M. Henn , Gregory P. Korchemsky , Peter Marquard

We analyze the cusp anomalous dimension in the (leading) ladder limit of $\mathcal N=4$ SYM and present new results for its higher-order perturbative expansion. We study two different limits with respect to the cusp angle $\phi$. The first…

High Energy Physics - Theory · Physics 2016-06-29 Matteo Beccaria , Alberto Fachechi , Guido Macorini

We introduce a method for extracting the cusp anomalous dimension at L loops from four-gluon amplitudes in N=4 Yang-Mills without evaluating any integrals that depend on the kinematical invariants. We show that the anomalous dimension only…

High Energy Physics - Theory · Physics 2008-11-26 Freddy Cachazo , Marcus Spradlin , Anastasia Volovich

We report first results of an ongoing project devoted to the analytical calculation of the QCD $\beta$-function and the quark mass anomalous dimension at the five loop level.

High Energy Physics - Phenomenology · Physics 2014-02-27 P. A. Baikov , K. G. Chetyrkin , J. H. Kühn

The four-loop beta-function of quantum chromodynamics is calculated and agreement is found with the previous result. The anomalous dimensions of the quark-gluon vertex, and quark, gluon and ghost fields are given for a general compact…

High Energy Physics - Phenomenology · Physics 2010-04-06 M. Czakon

We calculate the complete quark and gluon cusp anomalous dimensions in four-loop massless QCD analytically from first principles. In addition, we determine the complete matter dependence of the quark and gluon collinear anomalous…

High Energy Physics - Phenomenology · Physics 2020-05-12 Andreas von Manteuffel , Erik Panzer , Robert M. Schabinger

We report on a completely analytical calculation of the field anomalous dimension $\gamma_{\varphi}$ and the critical exponent $\eta$ for the $O(n)$-symmetric $\varphi^4$ model at the record six loop level. We successfully compare our…

High Energy Physics - Theory · Physics 2016-03-16 D. V. Batkovich , M. V. Kompaniets , K. G. Chetyrkin

We present the full analytic result for the three-loop angle-dependent cusp anomalous dimension in QCD. With this result, infrared divergences of planar scattering processes with massive particles can be predicted to that order. Moreover,…

High Energy Physics - Phenomenology · Physics 2015-03-05 Andrey Grozin , Johannes M. Henn , Gregory P. Korchemsky , Peter Marquard

We present results on the two-loop anomalous dimensions of the heavy baryon HQET currents $J=(q^TC\Gamma\tau q)\Gamma'Q$ with arbitrary Dirac matrices $\Gamma$ and $\Gamma'$. From our general result we obtain the two-loop anomalous…

High Energy Physics - Phenomenology · Physics 2009-10-28 S. Groote , J. G. Körner , O. I. Yakovlev
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