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Related papers: Three loop master integrals for ${\mathcal{O}} (\a…

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In this paper we study the calculation of multiloop Feynman integrals that cannot be expressed in terms of multiple polylogarithms. We show in detail how certain types of two- and three-point functions at two loops, which appear in the…

High Energy Physics - Phenomenology · Physics 2019-06-26 Johannes Broedel , Claude Duhr , Falko Dulat , Brenda Penante , Lorenzo Tancredi

We present an analytical calculation of the two-loop QCD corrections to the electromagnetic form factor of heavy quarks. The two-loop contributions to the form factor are reduced to linear combinations of master integrals, which are…

High Energy Physics - Phenomenology · Physics 2009-07-29 J. Gluza , A. Mitov , S. Moch , T. Riemann

The three-loop QCD contributions to the vacuum polarization functions of the $Z$ and $W$ bosons at zero momentum are calculated. The top quark is considered to be massive and the other quarks massless. Using these results, we calculate the…

High Energy Physics - Phenomenology · Physics 2011-01-13 L. Avdeev , J. Fleischer , S. Mikhailov , O. Tarasov

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 a calculation of the master integrals (MI's) required for the calculation of the Electroweak corrections to $gg\rightarrow \gamma\gamma$ production in which the process contains a light quark loop. The integrals can be broken…

High Energy Physics - Phenomenology · Physics 2024-03-29 Gabriele Fiore , Ciaran Williams

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 compute the full set of two-loop Feynman integrals appearing in massless two-loop four-point functions with two off-shell legs with the same invariant mass. These integrals allow to determine the two-loop corrections to the amplitudes…

High Energy Physics - Phenomenology · Physics 2014-06-13 Thomas Gehrmann , Andreas von Manteuffel , Lorenzo Tancredi , Erich Weihs

We consider Feynman integrals with algebraic leading singularities and total differentials in $\epsilon\,\mathrm{d}\ln$ form. We show for the first time that it is possible to evaluate integrals with singularities involving unrationalizable…

High Energy Physics - Theory · Physics 2020-08-18 Matthias Heller , Andreas von Manteuffel , Robert M. Schabinger

We calculate analytically the two-loop triangle integrals entering the $\mathcal{O}(\alpha\alpha_s)$ corrections to the $HZV$ vertex with $V=Z^*,\gamma^*$ using the method of differential equations. Our result provides a prototype to study…

High Energy Physics - Phenomenology · Physics 2019-10-23 Yuxuan Wang , Xiaofeng Xu , Li Lin Yang

The two-loop QCD corrections to vector boson pair production at hadron colliders involve a new class of Feynman integrals: two-loop four-point functions with two off-shell external legs. We describe their reduction to a small set of master…

High Energy Physics - Phenomenology · Physics 2013-08-26 Thomas Gehrmann , Lorenzo Tancredi , Erich Weihs

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 provide a compendium of techniques that can be used to compute $O(N_f\alpha^2)$ corrections to low-energy electroweak processes. Specifically, these are the 2-loop electroweak corrections containing a light fermion loop. It is shown that…

High Energy Physics - Phenomenology · Physics 2007-05-23 R. Akhoury , Paresh Malde , Robin G. Stuart

We calculate analytically the three-loop planar master integrals relevant for heavy-to-light form factors using the method of differential equations. After choosing a proper canonical basis, the boundary conditions are easy to be…

High Energy Physics - Phenomenology · Physics 2018-10-24 Long-Bin Chen , Jian Wang

The four-loop QCD corrections to the electroweak $\rho$-parameter arising from top and bottom quark loops are computed. Specifically we evaluate the missing ``non-singlet'' piece. Using algebraic methods the amplitude is reduced to a set of…

High Energy Physics - Phenomenology · Physics 2008-11-26 K. G. Chetyrkin , M. Faisst , J. H. Kühn , P. Maierhoefer , C. Sturm

We present the Master Integrals needed for the calculation of the two-loop QCD corrections to the forward-backward asymmetry of a quark-antiquark pair produced in electron-positron annihilation events. The abelian diagrams entering in the…

High Energy Physics - Phenomenology · Physics 2009-11-10 R. Bonciani , P. Mastrolia , E. Remiddi

We present the electroweak corrections for the production of a photon pair through gluon fusion, focusing on the contribution from the first two generations of quarks. The two-loop amplitude is calculated using a series of projection…

High Energy Physics - Phenomenology · Physics 2025-12-09 Gabriele Fiore , Ciaran Williams

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

We present the calculation of the mixed two-loop QCD/electroweak corrections to hadronic W boson decays within the Standard Model. The optical theorem is applied to the W boson two-point function. The multi-scale integrals are computed with…

High Energy Physics - Phenomenology · Physics 2015-12-01 Dominik Kara

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 calculate the full set of the two-loop master integrals for heavy-to-light form factors of two different massive fermions for arbitrary momentum transfer in NNLO QCD or QED corrections. These integrals allow to determine the two-loop QCD…

High Energy Physics - Phenomenology · Physics 2018-04-04 Long-Bin Chen