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Related papers: Two-loop Master Integrals with the Simplified Diff…

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We calculate two-loop master integrals for the process of heavy lepton pair production in $e^+e^-$ collisions. We consider the $C$-odd diagrams with three photons in the intermediate state and evaluate the corresponding families of the…

High Energy Physics - Phenomenology · Physics 2019-01-24 Roman N. Lee , Kirill T. Mingulov

A new approach to compute Feynman Integrals is presented. It relies on an integral representation of a given Feynman Integral in terms of simpler ones. Using this approach, we present, for the first time, results for a certain family of…

High Energy Physics - Phenomenology · Physics 2020-03-18 Costas G. Papadopoulos , Christopher Wever

We compute all two-loop master integrals which are required for the evaluation of next-to-leading order QCD corrections in Higgs boson production via gluon fusion. Many two-loop amplitudes for 2 -> 1 processes in the Standard Model and…

High Energy Physics - Phenomenology · Physics 2010-10-27 Charalampos Anastasiou , Stefan Beerli , Stefan Bucherer , Alejandro Daleo , Zoltan Kunszt

The two-loop box contributions to massive Bhabha scattering may be reduced to two-loop box master integrals (MIs) with five, six, and seven internal lines, plus vertices and self energies. The self-energy and vertex MIs may be solved…

High Energy Physics - Phenomenology · Physics 2009-11-11 M. Czakon , J. Gluza , K. Kajda , T. Riemann

We present the analytic calculation of all master integrals for 3-, 4-, and 5-particle semi-inclusive cuts of four-loop massless propagators by means of differential equations. We fix the integration constants by reducing the semi-inclusive…

High Energy Physics - Phenomenology · Physics 2025-03-26 Vitaly Magerya , Levente Fekésházy

We present analytical results for all master integrals for massless three-point functions, with one off-shell leg, at four loops. Our solutions were obtained using differential equations and direct integration techniques. We review the…

A short pedagogical introduction to a differential method used to calculate multi-loop scalar integrals is presented. As an example it is shown how to obtain, using the method, large mass expansion of the two loop sunrise master integrals.

High Energy Physics - Phenomenology · Physics 2011-03-17 M. Czachor , H. Czyz

We describe a new method of calculation of generic multi-loop master integrals based on the numerical solution of systems of difference equations in one variable. We show algorithms for the construction of the systems using…

High Energy Physics - Phenomenology · Physics 2009-07-09 S. Laporta

We calculate the three-loop master integrals contributing to the three-loop five-point amplitude on the special Coulomb branch of $\mathcal{N}=4$ SYM theory. For the genuine pentagon integrals, we follow the approach of Ref. [JHEP 12 (2025)…

High Energy Physics - Theory · Physics 2026-05-19 Andrei V. Belitsky , Leonid V. Bork , Roman N. Lee , Andrei I. Onishchenko , Vladimir A. Smirnov

We compute the master integrals containing 2 and 3 massive propagators entering the planar amplitudes of the 2-loop electroweak form factor. The masses of the $W$, $Z$ and Higgs bosons are assumed to be degenerate. This work is a…

High Energy Physics - Phenomenology · Physics 2009-11-10 U. Aglietti , R. Bonciani

We discuss recent progress towards extending the Helac framework to the calculation of two-loop amplitudes. A general algorithm for the automated computation of two-loop integrands is described. The algorithm covers all the steps of the…

High Energy Physics - Phenomenology · Physics 2024-01-19 Giuseppe Bevilacqua , Dhimiter Canko , Costas Papadopoulos

We present the calculation of the master integrals needed for the two-loop QCDxEW corrections to $ q + \bar{q} \to l^- + l^+$ and $ q + \bar{q}' \to l^- + \overline{\nu} \, , $ for massless external particles. We treat W and Z bosons as…

High Energy Physics - Phenomenology · Physics 2016-10-12 Roberto Bonciani , Stefano Di Vita , Pierpaolo Mastrolia , Ulrich Schubert

We present the analytic computation of a family of non-planar master integrals which contribute to the two-loop scattering amplitudes for Higgs plus one jet production, with full heavy-quark mass dependence. These are relevant for the NNLO…

High Energy Physics - Phenomenology · Physics 2020-02-03 R. Bonciani , V. Del Duca , H. Frellesvig , J. M. Henn , M. Hidding , L. Maestri , F. Moriello , G. Salvatori , V. A. Smirnov

We present a method of computing any one-loop integral in lattice perturbation theory by systematically expanding around its continuum limit. At any order in the expansion in the lattice spacing, the result can be written as a sum of…

High Energy Physics - Phenomenology · Physics 2009-11-07 Thomas Becher , Kirill Melnikov

We compute the differential equations for the two remaining integral topologies contributing to the leading colour two-loop amplitudes for $pp \rightarrow t\bar{t}j$. We derive differential equations for the master integrals by solving the…

High Energy Physics - Phenomenology · Physics 2024-05-01 Simon Badger , Matteo Becchetti , Nicolò Giraudo , Simone Zoia

We compute the master integrals relevant for the two-loop corrections to pseudo-scalar quarkonium and leptonium production and decay. We present both analytic and high-precision numerical results. The analytic expressions are given in terms…

High Energy Physics - Phenomenology · Physics 2022-11-18 Samuel Abreu , Matteo Becchetti , Claude Duhr , Melih A. Ozcelik

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

Among the unitarity cuts of massless 4-loop propagators two classes have remained unknown until recently: 2-loop 3-particle cuts, and 1-loop 4-particle cuts. In this article we shall discuss the calculation that completes the master…

High Energy Physics - Phenomenology · Physics 2019-12-16 Vitaly Magerya , Andrey Pikelner

We extend the maximal unitarity method at two loops to double-box basis integrals with up to three external massive legs. We use consistency equations based on the requirement that integrals of total derivatives vanish. We obtain unique…

High Energy Physics - Theory · Physics 2025-05-08 Henrik Johansson , David A. Kosower , Kasper J. Larsen

Loop diagram calculations typically rely on reduction to a finite set of master integrals in $4 - 2\epsilon$ dimensions. It has been shown that for any problem, the masters can be chosen so that their coefficients are finite as $\epsilon…

High Energy Physics - Phenomenology · Physics 2022-04-06 Stephen P. Martin