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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 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

The $\epsilon$-expansion of several two-loop self-energy diagrams with different thresholds and one mass are calculated. On-shell results are reduced to multiple binomial sums which values are presented in analytical form.

High Energy Physics - Theory · Physics 2009-10-31 M. Yu. Kalmykov , O. Veretin

The master differential equations in the external square momentum p^2 for the master integrals of the two-loop sunrise graph, in n-continuous dimensions and for arbitrary values of the internal masses, are derived. The equations are then…

High Energy Physics - Theory · Physics 2010-04-06 M. Caffo , H. Czyz , S. Laporta , E. Remiddi

We present the complete set of planar master integrals relevant to the calculation of three-point functions in four-loop massless Quantum Chromodynamics. Employing direct parametric integrations for a basis of finite integrals, we give…

High Energy Physics - Phenomenology · Physics 2019-07-22 Andreas von Manteuffel , Robert M. Schabinger

This is a sequel of our previous paper where we described an algorithm to find a solution of differential equations for master integrals in the form of an $\epsilon$-expansion series with numerical coefficients. The algorithm is based on…

High Energy Physics - Phenomenology · Physics 2018-08-15 Roman N. Lee , Alexander V. Smirnov , Vladimir 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 evaluate the master integrals for the two-loop non-planar box-diagrams contributing to the elastic scattering of muons and electrons at next-to-next-to-leading order in QED. We adopt the method of differential equations and the Magnus…

High Energy Physics - Phenomenology · Physics 2018-09-17 Stefano Di Vita , Stefano Laporta , Pierpaolo Mastrolia , Amedeo Primo , Ulrich Schubert

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

All three-loop on-shell QCD Feynman integrals with two masses can be reduced to 27 master integrals. Here we calculate these master integrals, expanded in epsilon, both exactly in the mass ratio and as series in limiting cases.

High Energy Physics - Phenomenology · Physics 2009-12-27 S. Bekavac , A. G. Grozin , D. Seidel , V. A. Smirnov

We present an analytic calculation of three-loop four-point Feynman integrals with two off-shell legs of equal mass. We provide solutions to the canonical differential equations of two integral families in both Euclidean and physical…

High Energy Physics - Phenomenology · Physics 2024-12-24 Ming-Ming Long

The scalar two-loop self-energy master diagram is studied in the case of arbitrary masses. Analytical results in terms of Lauricella- and Appell-functions are presented for the imaginary part. By using the dispersion relation a…

High Energy Physics - Phenomenology · Physics 2009-10-28 S. Bauberger , M. Boehm

We compute the two-loop master integrals for non-leptonic heavy-to-heavy decays analytically in a recently-proposed canonical basis. For this genuine two-loop, two-scale problem we first derive a basis for the master integrals that…

High Energy Physics - Phenomenology · Physics 2015-05-20 Tobias Huber , Susanne Krankl

We present an algorithm to evaluate multiloop Feynman integrals with an arbitrary number of internal massive lines, with the masses being in general complex-valued, and its implementation in the \textsc{Mathematica} package…

High Energy Physics - Phenomenology · Physics 2022-10-24 Tommaso Armadillo , Roberto Bonciani , Simone Devoto , Narayan Rana , Alessandro Vicini

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 compute all master integrals for massless three-loop four-particle scattering amplitudes required for processes like di-jet or di-photon production at the LHC. We present our result in terms of a Laurent expansion of the integrals in the…

High Energy Physics - Phenomenology · Physics 2020-05-20 Johannes Henn , Bernhard Mistlberger , Vladimir A. Smirnov , Pascal Wasser

We evaluate a four-loop conformal integral, i.e. an integral over four four-dimensional coordinates, by turning to its dimensionally regularized version and applying differential equations for the set of the corresponding 213 master…

High Energy Physics - Theory · Physics 2016-11-23 Burkhard Eden , Vladimir A. Smirnov

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

The calculation of exclusive observables beyond the one-loop level requires elaborate techniques for the computation of multi-leg two-loop integrals. We discuss how the large number of different integrals appearing in actual two-loop…

High Energy Physics - Phenomenology · Physics 2008-11-26 T. Gehrmann , E. Remiddi

Exploring the idea of Broadhurst on the ``sixth root of unity'' we present an ansatz for construction of a basis of transcendental numbers for the epsilon-expansion of single mass scale diagrams with two particle massive cut. As example,…

High Energy Physics - Phenomenology · Physics 2009-10-31 J. Fleischer , M. Yu. Kalmykov