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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

In this paper we compute the relation between heavy quark masses defined in the modified minimal subtraction and on-shell scheme. Detailed results are presented for all coefficients of the SU$(N_c)$ colour factors. The reduction of the…

High Energy Physics - Phenomenology · Physics 2016-11-23 Peter Marquard , Alexander V. Smirnov , Vladimir A. Smirnov , Matthias Steinhauser , David Wellmann

We calculate the one-loop QCD corrections for the decay of an off-shell vector boson with vector couplings into two pairs of quarks of equal or unequal flavours keeping all orders in the number of colours. These matrix elements are relevant…

High Energy Physics - Phenomenology · Physics 2008-11-26 E. W. N. Glover , D. J. Miller

We compute the on-shell wave function renormalization constant to four-loop order in QCD and present numerical results for all coefficients of the SU$(N_c)$ colour factors. We extract the four-loop HQET anomalous dimension of the heavy…

High Energy Physics - Phenomenology · Physics 2018-04-04 Peter Marquard , Alexander V. Smirnov , Vladimir A. Smirnov , Matthias Steinhauser

The four-loop Sudakov form factor in maximal super Yang-Mills theory is analysed in detail. It is shown explicitly how to construct a basis of integrals that have a uniformly transcendental expansion in the dimensional regularisation…

High Energy Physics - Theory · Physics 2018-12-17 Rutger H. Boels , Tobias Huber , Gang Yang

We compute the three-loop corrections to the quark axial vector form factor in massless QCD, focusing on the pure-singlet contributions where the axial vector current couples to a closed quark loop. Employing the Larin prescription for…

High Energy Physics - Phenomenology · Physics 2021-03-24 T. Gehrmann , A. Primo

We report on the complete three-loop corrections to the Higgs-gluon form factor in QCD. While previous calculations are based on QCD with a single heavy quark of arbitrary mass, we extend the study to QCD involving two different massive…

High Energy Physics - Phenomenology · Physics 2024-02-28 Marco Niggetiedt , Johann Usovitsch

We compute the eighth-order fermionic corrections involving two and three closed massless fermion loops to the anomalous magnetic moment of the muon. The required four-loop on-shell integrals are classified and explicit analytical results…

High Energy Physics - Phenomenology · Physics 2015-06-12 Roman Lee , Peter Marquard , Alexander V. Smirnov , Vladimir A. Smirnov , Matthias Steinhauser

We evaluate, exactly in d, the master integrals contributing to massless three-loop QCD form factors. The calculation is based on a combination of a method recently suggested by one of the authors (R.L.) with other techniques: sector…

High Energy Physics - Phenomenology · Physics 2015-03-13 R. N. Lee , A. V. Smirnov , V. A. Smirnov

We compute the photon-quark and Higgs-gluon form factors to four-loop order within massless perturbative Quantum Chromodynamics. Our results constitute ready-to-use building blocks for N${}^4$LO cross sections for Drell-Yan processes and…

We compute the three-loop non-singlet corrections to the photon-quark form factors taking into account the full dependence on the virtuality of the photon and the quark mass. We combine the method of differential equations in an effective…

High Energy Physics - Phenomenology · Physics 2022-05-11 Matteo Fael , Fabian Lange , Kay Schoenwald , Matthias Steinhauser

We present an analytic computation of the two-loop QCD corrections to $u\bar{d}\to W^+b\bar{b}$ for an on-shell $W$-boson using the leading colour and massless bottom quark approximations. We perform an integration-by-parts reduction of the…

High Energy Physics - Phenomenology · Physics 2021-10-14 Simon Badger , Heribertus Bayu Hartanto , Simone Zoia

We evaluate the planar two-loop QCD diagrams contributing to the leading color coefficient of the heavy-quark pair production cross section, in the quark-antiquark annihilation channel. We obtain the leading color coefficient in an analytic…

High Energy Physics - Phenomenology · Physics 2009-09-25 R. Bonciani , A. Ferroglia , T. Gehrmann , C. Studerus

We present the analytical calculation of the four-loop quark mass anomalous dimension in Quantum Chromodynamics within the minimal subtraction scheme. On the basis of this result we find that the so-called invariant quark mass is a very…

High Energy Physics - Phenomenology · Physics 2009-10-30 J. A. M. Vermaseren , S. A. Larin , T. van Ritbergen

We report on recent progress on the flavour non-singlet splitting functions in perturbative QCD. The~exact four-loop (N^3LO) contribution to these functions has been obtained in the planar limit of a large number of colours.…

High Energy Physics - Phenomenology · Physics 2018-01-19 A. Vogt , S. Moch , B. Ruijl , T. Ueda , J. A. M. Vermaseren

We numerically evaluate the two-loop QCD squared matrix element for in $q\bar{q}\to Z$ and $q\bar{q}\to Z\gamma$ with heavy top and bottom quarks circulating in a triangular fermion loop, by simultaneously subtracting infrared, ultraviolet,…

High Energy Physics - Phenomenology · Physics 2026-03-04 Dario Kermanschah , Matilde Vicini

We review on the calculation of the heavy-quark photo-production vector form factors, with the full dependence on the mass of the heavy-quark. The Feynman diagrams are evaluated within the dimensional regularization scheme and expressed in…

High Energy Physics - Phenomenology · Physics 2015-06-25 R. Bonciani

We calculate the two-loop QCD correction to the form factors of on-shell b-quark decay to an energetic massless quark, which constitutes the last missing piece required for an O(alpha_s^2) determination of |V_ub| from inclusive…

High Energy Physics - Phenomenology · Physics 2014-11-18 M. Beneke , T. Huber , Xin-Qiang Li

We present a computation of the one-loop QCD corrections to top-quark pair production in association with a $W$ boson, including terms up to order $\varepsilon^2$ in dimensional regularization. Providing a first glimpse into the complexity…

High Energy Physics - Phenomenology · Physics 2025-11-05 Matteo Becchetti , Maximilian Delto , Sara Ditsch , Philipp Alexander Kreer , Mattia Pozzoli , Lorenzo Tancredi

We consider Quantum Chromodynamics with external vector, axial-vector, scalar and pseudo-scalar currents and compute three-loop corrections to the corresponding vertex function taking into account massive quarks. We consider all non-singlet…

High Energy Physics - Phenomenology · Physics 2022-09-14 Matteo Fael , Fabian Lange , Kay Schönwald , Matthias Steinhauser