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Related papers: Progress on two-loop non-propagator integrals

200 papers

We compute for the first time the two-loop five-particle amplitude in $\mathcal{N}=8$ supergravity. Starting from the known integrand, we perform an integration-by-parts reduction and express the answer in terms of uniform weight master…

High Energy Physics - Theory · Physics 2019-05-01 D. Chicherin , T. Gehrmann , J. M. Henn , P. Wasser , Y. Zhang , S. Zoia

We present a semi-numerical algorithm to calculate one-loop virtual corrections to scattering amplitudes. The divergences of the loop amplitudes are regulated using dimensional regularization. We treat in detail the case of amplitudes with…

High Energy Physics - Phenomenology · Physics 2008-11-26 R. K. Ellis , W. T. Giele , G. Zanderighi

In this paper, we focus on both analytical expressions of three and four point integrals for the case of small Gram determinant and numerical improvement of $n$-point integrals for $n\ge5$. Explicit expressions of three and four-point…

High Energy Physics - Phenomenology · Physics 2010-02-09 Kwangwoo Park

The calculation of the two-loop corrections to the three jet production rate and to event shapes in electron-positron annihilation requires the computation of a number of up to now unknown two-loop four-point master integrals with one…

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

We describe the formalism to compute gravitational-wave observables for compact binaries via the effective field theory framework in combination with modern tools from collider physics. We put particular emphasis on solving the "multi-loop"…

High Energy Physics - Theory · Physics 2023-04-05 Christoph Dlapa , Gregor Kälin , Zhengwen Liu , Rafael A. Porto

In perturbation theory, the spectral densities of two-point functions develop non-integrable threshold singularities at higher orders. In QCD, such singularities emerge when calculating the diagrams in terms of the pole quark mass, and they…

High Energy Physics - Phenomenology · Physics 2021-01-20 Dmitri Melikhov , Silvano Simula

We use unitarity techniques to compute the two-loop non-planar corrections to the Sudakov form factor and the four-point amplitude in ABJM theory. We start by reconstructing non-planar integrals from two-particle cuts in three dimensions.…

High Energy Physics - Theory · Physics 2014-07-09 Lorenzo Bianchi , Marco S. Bianchi

We study a recently-proposed approach to the numerical evaluation of multi-loop Feynman integrals using available sector decomposition programs. As our main example, we consider the two-loop integrals for the $\alpha \alpha_s$ corrections…

High Energy Physics - Phenomenology · Physics 2017-11-08 Andreas von Manteuffel , Robert M. Schabinger

Supersymmetric integrands for the two-loop five-point amplitudes in ten-dimensional super Yang--Mills and type II supergravity are proposed. The kinematic numerators are manifestly local and satisfy the duality between color and kinematics…

High Energy Physics - Theory · Physics 2015-11-05 Carlos R. Mafra , Oliver Schlotterer

Evaluation of three- and four-point diagrams with massless internal particles and arbitrary external momenta is considered. Exact results for some two-loop diagrams (planar and non-planar three-point contributions and the "double box"…

High Energy Physics - Phenomenology · Physics 2007-05-23 N. I. Ussyukina , A. I. Davydychev

We present the first numerical computation of two-loop amplitudes based on the unitarity method. As a proof of principle, we compute the four-gluon process. We discuss the new method, analyze its numerical properties and apply it to…

High Energy Physics - Phenomenology · Physics 2017-10-11 S. Abreu , F. Febres Cordero , H. Ita , M. Jaquier , B. Page , M. Zeng

We compute the coefficient of the potential three-loop divergence in pure N=4 supergravity and show that it vanishes, contrary to expectations from symmetry arguments. The recently uncovered duality between color and kinematics is used to…

High Energy Physics - Theory · Physics 2013-05-30 Zvi Bern , Scott Davies , Tristan Dennen , Yu-tin Huang

A fully numerical method to calculate loop integrals, a numerical contour-integration method, is proposed. Loop integrals can be interpreted as a contour integral in a complex plane for an integrand with multi-poles in the plane. Stable and…

High Energy Physics - Phenomenology · Physics 2009-11-11 Y. Kurihara , T. Kaneko

In this work, we investigate the finite basis topologies of two-loop dimensionally regularized Feynman integrals in the `t Hooft-Veltman scheme in the Standard Model. We present a functionally distinct finite basis of Master Integrals which…

High Energy Physics - Theory · Physics 2025-03-28 Piotr Bargiela , Tong-Zhi Yang

We recently presented a new method for the evaluation of one-loop amplitude of arbitrary scattering processes, in which the reduction to scalar integrals is performed at the integrand level. In this talk, we review the main features of the…

High Energy Physics - Phenomenology · Physics 2007-09-17 Giovanni Ossola

We review some of the recent advances in the computation of one-loop scattering amplitudes which led to the construction of efficient and automated computational tools for NLO predictions. Particular attention is devoted to unitarity-based…

High Energy Physics - Phenomenology · Physics 2015-06-17 Giovanni Ossola

In this article we compute the action of the two loop dilatation operator on restricted Schur polynomials that belong to the su(2) sector, in the displaced corners approximation. In this non-planar large N limit, operators that diagonalize…

High Energy Physics - Theory · Physics 2015-06-05 Robert de Mello Koch , Garreth Kemp , Badr Awad Elseid Mohammed , Stephanie Smith

We find general solutions for the dimensionally regularised scalar one loop three-point and four-point functions with one heavy quark propagator. The scalar one-point function vanishes, while the expression for the two-point function has…

High Energy Physics - Phenomenology · Physics 2009-01-07 J. Zupan

A simple formula for one-loop logarithmic divergences on the background of a two-dimensional curved space-time is derived for theories for which the second variation of the action is a nonminimal second order operator with small nonminimal…

High Energy Physics - Theory · Physics 2016-07-20 H. P. Popova , K. V. Stepanyantz

We report on recent progress on the flavour non-singlet splitting functions in perturbative QCD. The~exact four-loop (N^3LO) contribution to these functions has been obtained in the planar limit of a large number of colours.…

High Energy Physics - Phenomenology · Physics 2018-01-19 A. Vogt , S. Moch , B. Ruijl , T. Ueda , J. A. M. Vermaseren