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Related papers: Three loop QCD corrections to the heavy-light form…

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The calculation of massive three-loop QCD form factors using in particular the large moments method has been successfully applied to quarkonic contributions in [1]. We give a brief review of the different steps of the calculation and report…

High Energy Physics - Phenomenology · Physics 2024-08-14 J Blümlein , A. De Freitas , P. Marquard , C. Schneider

We present the leading colour and light fermionic planar two-loop corrections for the production of two photons and a jet in the quark-antiquark and quark-gluon channels. In particular, we compute the interference of the two-loop amplitudes…

High Energy Physics - Phenomenology · Physics 2021-05-05 Bakul Agarwal , Federico Buccioni , Andreas von Manteuffel , Lorenzo Tancredi

We compute the four-loop contributions to the photon quark and Higgs quark form factors involving two closed fermion loops. We present analytical results for all non-planar master integrals of the two non-planar integral families which…

High Energy Physics - Phenomenology · Physics 2017-07-19 Roman N. Lee , Alexander V. Smirnov , Vladimir A. Smirnov , Matthias Steinhauser

We compute the three-loop QCD corrections to the massive quark-anti-quark-photon form factors $F_1$ and $F_2$ in the large-$N_c$ limit. The analytic results are expressed in terms of Goncharov polylogarithms. This allows for a…

High Energy Physics - Phenomenology · Physics 2017-03-08 Johannes Henn , Alexander V. Smirnov , Vladimir A. Smirnov , Matthias Steinhauser

We present the analytic results for the non-singlet contributions to the three-loop mixed strong-electroweak ${\mathcal{O}}(\alpha_s^2\alpha)$ virtual corrections to the quark form factors. The primary challenge of this computation arises…

High Energy Physics - Phenomenology · Physics 2025-12-30 Tanmoy Pati , Narayan Rana , V. Ravindran

We compute the three-loop corrections to the potential of two heavy quarks. In particular we consider in this Letter the purely gluonic contribution which provides in combination with the fermion corrections of Ref. \cite{Smirnov:2008pn}…

High Energy Physics - Phenomenology · Physics 2010-04-23 Alexander V. Smirnov , Vladimir A. Smirnov , Matthias Steinhauser

The quarkonic contributions to the three-loop heavy-quark form factors for vector, axial-vector, scalar and pseudoscalar currents are described by closed form difference equations for the expansion coefficients in the limit of small…

High Energy Physics - Phenomenology · Physics 2023-07-07 Johannes Blümlein , Abilio De Freitas , Peter Marquard , Narayan Rana , Carsten Schneider

We present the three-loop QCD corrections to the quark chromomagnetic moment including two different nonzero masses. This is a necessary ingredient to obtain the corresponding corrections to the chromomagnetic coefficient in the Heavy Quark…

High Energy Physics - Phenomenology · Physics 2009-06-02 S. Bekavac , A. Grozin , D. Seidel , M. Steinhauser

We numerically compute the two-loop QCD corrections to $Z\gamma$ production at the LHC mediated by light- and heavy-quark box loops. The calculation employs the pipeline of refs. arXiv:2407.18051 and arXiv:2510.18801, which performs Monte…

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

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

We present results of a perturbative matching calculation performed at one-loop for heavy-light currents. We use the Fermilab action for the heavy quarks, the Asqtad action for the light quarks, and an improved gluon action. We also present…

High Energy Physics - Lattice · Physics 2010-11-19 Aida X. El-Khadra , Elvira Gámiz , Andreas S. Kronfeld , Matthew A. Nobes

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 consider the three-loop corrections to the static potential which are induced by a closed fermion loop. For the reduction of the occurring integrals a combination of the Gr\"obner and Laporta algorithm has been used and the evaluation of…

High Energy Physics - Phenomenology · Physics 2008-11-26 Alexander V. Smirnov , Vladimir A. Smirnov , Matthias Steinhauser

In this letter we continue the calculation of master integrals for massless three-loop form factors by giving analytical results for those integrals which are relevant for the fermionic contributions proportional to N_F^2, N_F*N, and N_F/N.…

High Energy Physics - Phenomenology · Physics 2008-11-26 G. Heinrich , T. Huber , D. Maitre

We compute the fermionic contribution to the photon-quark form factor to four-loop order in QCD in the planar limit in analytic form. From the divergent part of the latter the cusp and collinear anomalous dimensions are extracted. Results…

High Energy Physics - Phenomenology · Physics 2016-04-19 Johannes M. Henn , Alexander V. Smirnov , Vladimir A. Smirnov , Matthias Steinhauser

A method of computing two-loop fermionic contributions to the width of a heavy quark is described. An analytical formula for this effect in the limit of mass of the quark much larger than the decay products is obtained for the first time.…

High Energy Physics - Phenomenology · Physics 2011-03-02 Andrzej Czarnecki

We present closed analytic expressions of the electromagnetic vertex form factors for heavy quarks at the two-loop level in QCD for arbitrary momentum transfer. The calculation is carried out in dimensional regularization. The electric and…

High Energy Physics - Phenomenology · Physics 2010-04-05 W. Bernreuther , R. Bonciani , T. Gehrmann , R. Heinesch , T. Leineweber , P. Mastrolia , E. Remiddi

We compute three-loop corrections to the singlet form factors for massive quarks using a semi-analytic method which provides precise results over the whole kinematic range. Particular emphasis is put on the anomaly contribution originating…

High Energy Physics - Phenomenology · Physics 2023-05-24 Matteo Fael , Fabian Lange , Kay Schönwald , Matthias Steinhauser

We present the results for heavy quark form factors at two-loop order in perturbative QCD for different currents, namely vector, axial-vector, scalar and pseudo-scalar currents, up to second order in the dimensional regularization…

High Energy Physics - Phenomenology · Physics 2018-05-09 J. Ablinger , A. Behring , J. Blümlein , G. Falcioni , A. De Freitas , P. Marquard , N. Rana , C. Schneider

In this thesis, we study the three-loop QCD form factors. After an introduction and a discussion of the physics motivation, we generate the quark form factor using Qgraf. We then show how to bring the Feynman integrals into a unique form by…

High Energy Physics - Phenomenology · Physics 2009-03-04 Beat Toedtli