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Related papers: Singlet and non-singlet three-loop massive form fa…

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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 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

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 compute the three-loop QCD corrections to the massive quark form factors with external vector, axial-vector, scalar and pseudo-scalar currents. All corrections with closed loops of massless fermions are included. The non-fermionic part…

High Energy Physics - Phenomenology · Physics 2018-07-04 Roman N. Lee , Alexander V. Smirnov , Vladimir A. Smirnov , Matthias Steinhauser

We compute the matching coefficients between QCD and non-relativistic QCD for external vector, axial-vector, scalar and pseudo-scalar currents up to three-loop order. We concentrate on the non-singlet contributions and present precise…

High Energy Physics - Phenomenology · Physics 2022-06-22 Manuel Egner , Matteo Fael , Fabian Lange , Kay Schönwald , Matthias Steinhauser

We compute the color-planar and complete light quark non-singlet contributions to the heavy quark form factors in the case of the axialvector, scalar and pseudoscalar currents at three loops in perturbative QCD. We evaluate the master…

High Energy Physics - Phenomenology · Physics 2018-08-01 J. Ablinger , J. Blümlein , P. Marquard , N. Rana , C. Schneider

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 present closed analytic expressions for the order $\alpha_s^2$ triangle diagram contributions to the matrix elements of the singlet and non-singlet axial vector currents between the vacuum and a quark-antiquark state. We have calculated…

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

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 three-loop corrections of $\mathcal{O}(\alpha_{s}^3)$ to form factors with one massive and one massless quark coupling to an external vector, axialvector, scalar, pseudoscalar, or tensor current. We obtain analytic results for…

High Energy Physics - Phenomenology · Physics 2024-09-24 Matteo Fael , Tobias Huber , Fabian Lange , Jakob Müller , Kay Schönwald , Matthias Steinhauser

We compute the three-loop QCD corrections to the massive quark-anti-quark-photon form factors $F_1$ and $F_2$ involving a closed loop of massless fermions. This subset is gauge invariant and contains both planar and non-planar…

High Energy Physics - Phenomenology · Physics 2018-04-18 Roman N. Lee , Alexander V. Smirnov , Vladimir A. Smirnov , Matthias Steinhauser

We report on our recent calculation of massive quark form factors using a semi-numerical approach based on series expansions of the master integrals around singular and regular kinematic points and numerical matching. The methods allows to…

High Energy Physics - Phenomenology · Physics 2022-07-15 Kay Schönwald

We present the bare one-, two-, and three-loop form factors in massless Quantum Chromodynamics as linear combinations of finite master integrals. Using symbolic integration, we compute their $\epsilon$ expansions and thereby reproduce all…

High Energy Physics - Phenomenology · Physics 2016-08-30 Andreas von Manteuffel , Erik Panzer , Robert M. Schabinger

We present the color planar and complete light quark QCD contributions to the three loop heavy quark form factors in the case of vector, axial-vector, scalar and pseudo-scalar currents. We evaluate the master integrals applying a new method…

High Energy Physics - Phenomenology · Physics 2018-07-18 Jakob Ablinger , Johannes Bluemlein , Peter Marquard , Narayan Rana , Carsten Schneider

We evaluate the three-loop corrections to the matching coefficient of the vector current between Quantum Chromodynamics (QCD) and non-relativistic QCD. The result is presented in the MSbar scheme where large perturbative corrections are…

High Energy Physics - Phenomenology · Physics 2014-03-05 Peter Marquard , Jan H. Piclum , Dirk Seidel , Matthias Steinhauser

A summary of the calculation of the color-planar and complete light quark contributions to the massive three-loop form factors is presented. Here a novel calculation method for the Feynman integrals is used, solving general uni-variate…

High Energy Physics - Phenomenology · Physics 2019-06-14 J. Ablinger , J. Blümlein , P. Marquard , N. Rana , C. Schneider

We present analytic results for three-loop fermionic corrections to the heavy-light form factors in perturbative quantum chromodynamics. Specifically, we present all light quark contributions and contributions from two heavy quark loops. We…

High Energy Physics - Phenomenology · Physics 2024-07-23 Sudeepan Datta , Narayan Rana

In this contribution we provide further details to the recent calculation of QCD corrections to massive three-loop form factors presented in Ref. [1].

High Energy Physics - Phenomenology · Physics 2018-07-26 Roman N. Lee , Alexander V. Smirnov , Vladimir A. Smirnov , Matthias Steinhauser

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 analytic expressions for the color-planar contributions to the heavy-light form factors at three loops in perturbative QCD. These form factors play an important role in the precision predictions of various observables in top…

High Energy Physics - Phenomenology · Physics 2023-08-24 Sudeepan Datta , Narayan Rana , V. Ravindran , Ratan Sarkar
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