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Related papers: Two-loop master integrals for $e^{+}e^{-}\rightarr…

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We briefly discuss an algorithm for the tensor reduction of the two-loop massless crossed boxes, with light-like external legs, and the computation of the relative master integrals.

High Energy Physics - Phenomenology · Physics 2009-10-31 Carlo Oleari

We carry out a systematic investigation of all the 2-loop integrals occurring in the electron vertex in QED in the continuous $D$-dimensional regularization scheme, for on-shell electrons, momentum transfer $t=-Q^2$ and finite squared…

High Energy Physics - Phenomenology · Physics 2008-11-26 R. Bonciani , P. Mastrolia , E. Remiddi

The total cross section of the process $e^+e^- \to \Lambda\bar{\Lambda}$ is calculated within the energy range close to the mass of $\psi(3770)$ charmonium state. Two different contributions were considered: the $D$-meson loop and the three…

High Energy Physics - Phenomenology · Physics 2022-06-29 Yu. M. Bystritskiy , A. I. Ahmadov

We present the calculation of the nf-contributions to the two-loop amplitude for e+ e- --> q qbar g and give results for the full one-loop amplitude to order eps^2 in the dimensional regularization parameter. Our results agree with those…

High Energy Physics - Phenomenology · Physics 2009-09-29 Sven Moch , Peter Uwer , Stefan Weinzierl

We compute the (three) master integrals for the crossed ladder diagram with two exchanged quanta of equal mass. The differential equations obeyed by the master integrals are used to generate power series expansions centered around all the…

High Energy Physics - Phenomenology · Physics 2008-11-26 U. Aglietti , R. Bonciani , L. Grassi , E. Remiddi

We discuss two-loop leading and angular-dependent next-to-leading logarithmic electroweak virtual corrections to arbitrary processes at energies above the electroweak scale. The relevant Feynman diagrams involving soft-collinear gauge…

High Energy Physics - Phenomenology · Physics 2008-11-26 Ansgar Denner , Michael Melles , Stefano Pozzorini

In this paper we describe a new method of calculation of master integrals based on the solution of systems of difference equations in one variable. An explicit example is given, and the generalization to arbitrary diagrams is described. As…

High Energy Physics - Phenomenology · Physics 2009-11-07 S. Laporta

For the two-loop next-to-leading-order electroweak (NLO EW) corrections to $gg \rightarrow ZH$, the light-fermion contributions can be classified into eight distinct topologies. Using the canonical differential-equations method, we perform…

High Energy Physics - Phenomenology · Physics 2026-05-01 Shu-Xiang Li , Ren-You Zhang , Xiao-Feng Wang , Pan-Feng Li , Xiang-Jie Wei , Yi Wang , Yi Jiang , Qing-hai Wang

We describe a generator for the process $e^+e^- \to W^+W^-$ including all one-loop and leading log photonic two-loop contributions. It includes polarization of the beam and $W$ bosons, and the possibility to study the effect of anomalous…

High Energy Physics - Phenomenology · Physics 2009-10-28 Jochem Fleischer , Fred Jegerlehner , Karol Kolodziej , Geert Jan van Oldenborgh

In this thesis, major developments in the publicly available program SecDec are presented, extending the numerical evaluation of multi-loop multi-scale integrals from Euclidean to physical kinematics. The power of this new feature is shown…

High Energy Physics - Phenomenology · Physics 2014-10-30 Sophia Borowka

We present the analytic computation of all the planar master integrals which contribute to the two-loop scattering amplitudes for Higgs$\to 3$ partons, with full heavy-quark mass dependence. These are relevant for the NNLO corrections to…

High Energy Physics - Phenomenology · Physics 2017-02-01 Roberto Bonciani , Vittorio Del Duca , Hjalte Frellesvig , Johannes M. Henn , Francesco Moriello , Vladimir A. Smirnov

We describe a method to numerically compute multi-loop integrals, depending on one dimensionless parameter $x$ and the dimension $d$, in the whole kinematic range of $x$. The method is based on differential equations, which, however, do not…

High Energy Physics - Phenomenology · Physics 2021-10-13 Matteo Fael , Fabian Lange , Kay Schönwald , Matthias Steinhauser

We present the program BOKASUN for fast and precise evaluation of the Master Integrals of the two-loop self-mass sunrise diagram for arbitrary values of the internal masses and the external four-momentum. We use a combination of two…

High Energy Physics - Phenomenology · Physics 2009-11-13 Michele Caffo , Henryk Czyz , Michal Gunia , Ettore Remiddi

We overview the general status of higher order corrections to Bhabha scattering and review recent progress in the determination of the two-loop virtual corrections. Quite recently, they were derived from combining a massless calculation and…

High Energy Physics - Phenomenology · Physics 2007-05-23 M. Czakon , J. Gluza , T. Riemann

We consider three-loop radiative-recoil corrections to hyperfine splitting in muonium due to insertions of one-loop polarization operator in the electron factor. The contribution generated by electron polarization insertions is a cubic…

High Energy Physics - Phenomenology · Physics 2011-05-12 Michael I. Eides , Valery A. Shelyuto

We present TVID 2, a program to numerically evaluate an important class of planar three-loop self-energy master integrals with arbitrary masses. As with the predecessor version (TVID 1) the integrals are separated into a known piece,…

High Energy Physics - Phenomenology · Physics 2020-01-09 Stefan Bauberger , Ayres Freitas , Daniel Wiegand

We discuss the calculation of the nf-contributions to the two-loop amplitude for e+ e- -> q qbar g. The calculation uses an efficient method based on nested sums. The result is presented in terms of multiple polylogarithms with simple…

High Energy Physics - Phenomenology · Physics 2007-05-23 S. Moch , P. Uwer , S. Weinzierl

The differential equation in the external invariant p^2 satisfied by the master integral of the general massive 2-loop 4-denominator self-mass diagram is exploited and the expansion of the master integral at p^2=0 is obtained analytically.…

High Energy Physics - Phenomenology · Physics 2010-04-05 M. Caffo , H. Czyz , A. Grzelinska , E. Remiddi

We present the complete analytical result for the two-loop logarithmically enhanced contributions to the high energy asymptotic behavior of the vector form factor and the four-fermion cross section in a spontaneously broken SU(2) gauge…

High Energy Physics - Phenomenology · Physics 2010-11-05 Bernd Jantzen , Johann H. Kühn , Alexander A. Penin , Vladimir A. Smirnov

The computation of Feynman integrals is often the bottleneck of multi-loop calculations. We propose and implement a new method to efficiently evaluate such integrals in the physical region through the numerical integration of a suitable set…

High Energy Physics - Phenomenology · Physics 2019-05-01 Manoj K. Mandal , Xiaoran Zhao