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We present an evaluation of the two master integrals for the crossed vertex diagram with a closed loop of top quarks that allows for an easy numerical implementation. The differential equations obeyed by the master integrals are used to…

High Energy Physics - Phenomenology · Physics 2019-06-26 Roberto Bonciani , Giuseppe Degrassi , Pier Paolo Giardino , Ramona Gröber

We extend the geometric framework of field-space covariance for loop computations, thereby unifying the treatment of scalars, fermions, and gauge bosons in effective field theories. This allows us to derive a manifestly covariant formula…

High Energy Physics - Phenomenology · Physics 2025-04-28 Benoît Assi , Andreas Helset , Julie Pagès , Chia-Hsien Shen

We present the results for two-loop massive kite master integrals with elliptics in terms of iterated integrals with algebraic kernels. The key ingredients are new integral representations for sunset subgraphs in $d=4-2\epsilon$ and…

High Energy Physics - Phenomenology · Physics 2021-02-24 M. A. Bezuglov , A. I. Onishchenko , O. L. Veretin

We consider the most general two-loop massless correlator $I(n_1,n_2,n_3,n_4,n_5; x,y;D)$ of two composite vertices with the Bjorken fractions $x$ and $y$ for arbitrary indices $\{n_i\}$ and space-time dimension $D$; this correlator is…

High Energy Physics - Theory · Physics 2022-06-16 S. V. Mikhailov , N. Volchanskiy

We compute the two-loop master integrals for leading-color QCD scattering amplitudes including a closed light-quark loop in $t\bar{t}H$ production at hadron colliders. Exploiting numerical evaluations in modular arithmetic, we construct a…

High Energy Physics - Phenomenology · Physics 2024-07-18 F. Febres Cordero , G. Figueiredo , M. Kraus , B. Page , L. Reina

We propose a multiloop generalization of the Bern-Kosower formalism, based on Strassler's approach of evaluating worldline path integrals by worldline Green functions. Those Green functions are explicitly constructed for the basic two-loop…

High Energy Physics - Theory · Physics 2009-10-28 M. G. Schmidt , C. Schubert

We consider two-loop renormalization of high-dimensional Lorentz scalar operators in the gluonic sector of QCD. These operators appear also in the Higgs effective theory obtained by integrating out the top quark loop in the gluon fusion…

High Energy Physics - Phenomenology · Physics 2021-05-05 Qingjun Jin , Ke Ren , Gang Yang

A recurrence relation between equal mass two-loop sunrise diagrams differing in dimensionality by 2 is derived and it's solution in terms of Gauss' 2F1 and Appell's F_2 hypergeometric functions is presented. For arbitrary space-time…

High Energy Physics - Phenomenology · Physics 2009-11-11 O. V. Tarasov

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 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

This article displays a proof of concept of the mixed analytical/numerical method, presented in previous publications, to compute two-loop functions with up to five massive propagators in a scalar theory having three- and four-leg vertices…

High Energy Physics - Phenomenology · Physics 2021-09-15 J. Ph. Guillet , E. Pilon , Y. Shimizu , M. S. Zidi

We give an algorithm for obtaining expansions of massive two-loop Feynman graphs in powers of the external momentum around a finite, nonzero value of the momentum. This is based on our general two-loop formalism to reduce massive two-loop…

High Energy Physics - Phenomenology · Physics 2009-10-31 A. Ghinculov , Y. P. Yao

We perform a two-loop calculation in light-front phi^4 theory to determine the effective mass renormalization of the light-front Hamiltonian. The renormalization scheme adopted here is manifestly boost invariant, and yields results that are…

High Energy Physics - Theory · Physics 2007-05-23 F. Antonuccio , J. O. Andersen

We address the problem of evaluation of multiloop Feynman integrals by means of their Mellin-Barnes representation. After a brief overview of available capabilities though open source toolkits and their application in various circumstances,…

High Energy Physics - Phenomenology · Physics 2023-01-25 A. V. Belitsky , A. V. Smirnov , V. A. Smirnov

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

Consider the Fourier transform on the group $GL(2,R)$ of real $2\times 2$-matrices. We show that Fourier-images of polynomial differential operators on $GL(2,R)$ are differential-difference operators with coefficients meromorphic in…

Representation Theory · Mathematics 2019-10-29 Yury A. Neretin

It is known that one-loop Feynman integrals possess an algebraic structure encoding some of their analytic properties called the coaction, which can be written in terms of Feynman integrals and their cuts. This diagrammatic coaction, and…

High Energy Physics - Theory · Physics 2019-12-16 Samuel Abreu , Ruth Britto , Claude Duhr , Einan Gardi , James Matthew

We use the method of differential equations to analytically evaluate all planar three-loop Feynman integrals relevant for form factor calculations involving massive particles. Our results for ninety master integrals at general $q^2$ are…

High Energy Physics - Phenomenology · Physics 2017-02-01 Johannes M. Henn , Alexander V. Smirnov , Vladimir A. Smirnov

We present the analytic calculation of the Master Integrals for the two-loop, non-planar topologies that enter the calculation of the amplitude for top-quark pair hadroproduction in the quark-annihilation channel. Using the method of…

High Energy Physics - Phenomenology · Physics 2019-09-04 Matteo Becchetti , Roberto Bonciani , Valerio Casconi , Andrea Ferroglia , Simone Lavacca , Andreas von Manteuffel

We present the analytic calculation of the planar master integrals which contribute to compute the two-loop light-fermion electroweak corrections to the production of a Higgs boson in association with a jet in gluon-gluon fusion. The…

High Energy Physics - Phenomenology · Physics 2018-12-26 Matteo Becchetti , Roberto Bonciani , Valerio Casconi , Vittorio Del Duca , Francesco Moriello
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