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Related papers: Two-loop amplitude generation in OpenLoops

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We introduce a novel construction of a contour deformation within the framework of Loop-Tree Duality for the numerical computation of loop integrals featuring threshold singularities in momentum space. The functional form of our contour…

High Energy Physics - Phenomenology · Physics 2020-11-24 Zeno Capatti , Valentin Hirschi , Dario Kermanschah , Andrea Pelloni , Ben Ruijl

We present analytic results for the finite diagrams contributing to the two-loop eight-point MHV scattering amplitude of planar N=4 SYM. We use a recently proposed representation for the integrand of the amplitude in terms of (momentum)…

High Energy Physics - Theory · Physics 2011-07-21 Luis F. Alday

We compute helicity amplitudes for the one-loop QCD corrections to top-quark pair production analytically in terms of a set of uniformly transcendental master integrals. We provide corrections up to $O(\epsilon^2)$ in the dimensional…

High Energy Physics - Phenomenology · Physics 2022-06-29 Simon Badger , Matteo Becchetti , Ekta Chaubey , Robin Marzucca , Francesco Sarandrea

We calculate the $gg\to\gamma\gamma$ amplitude by including the $t\bar t$ bound-state effects near their mass threshold. In terms of the non-relativistic expansion of the amplitude, the LO contribution is an energy-independent term in the…

High Energy Physics - Phenomenology · Physics 2017-06-02 Sayaka Kawabata , Hiroshi Yokoya

We compute the next-to-leading order (NLO) QCD corrections to the $1 \to 2$ splitting amplitudes in different dimensional regularization (DREG) schemes. Besides recovering previously known results, we explore new DREG schemes and analyze…

High Energy Physics - Phenomenology · Physics 2014-01-15 German F. R. Sborlini , Daniel de Florian , German Rodrigo

We present the universal two-loop splitting functions that describe the limits of two-loop $n$-point amplitudes of massless particles when two of the momenta are collinear. To derive the splitting amplitudes, we take the collinear limits of…

High Energy Physics - Phenomenology · Physics 2009-11-10 S. D. Badger , E. W. N. Glover

We calculate the contributions to the two-loop scattering amplitudes $h \to gg$, $h \to ggg$ and $h \to q \bar q g$ that arise from a modified trilinear Higgs coupling $\lambda$. Analytic expressions are obtained by performing an asymptotic…

High Energy Physics - Phenomenology · Physics 2019-05-01 Martin Gorbahn , Ulrich Haisch

Multiloop scattering amplitudes describing the quantum fluctuations at high-energy scattering processes are the main bottleneck in perturbative quantum field theory. The loop-tree duality is a novel method aimed at overcoming this…

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 hybrid formalism for the superstring is used to compute one-loop amplitudes with an arbitrary number of external d=4 supergravity states. These one-loop N-point amplitudes are expressed as Koba-Nielsen-like formulas with manifest d=4…

High Energy Physics - Theory · Physics 2009-11-07 Nathan Berkovits , Brenno Carlini Vallilo

We present analytic expressions for the one-loop QCD helicity amplitudes contributing to top-quark pair production in association with a photon or a jet at the Large Hadron Collider (LHC), evaluated through $\mathcal{O}(\epsilon^2)$ in the…

High Energy Physics - Phenomenology · Physics 2026-05-15 Souvik Bera , Colomba Brancaccio , Dhimiter Canko , Heribertus Bayu Hartanto

We present the first public version of Caravel, a C++17 framework for the computation of multi-loop scattering amplitudes in quantum field theory, based on the numerical unitarity method. Caravel is composed of modules for the…

High Energy Physics - Phenomenology · Physics 2021-07-28 S. Abreu , J. Dormans , F. Febres Cordero , H. Ita , M. Kraus , B. Page , E. Pascual , M. S. Ruf , V. Sotnikov

We employ the recently developed method of generalized $D$-dimensional unitarity to compute one-loop virtual corrections to all scattering amplitudes relevant for the production of a $W$ boson in association with three jets in hadronic…

High Energy Physics - Phenomenology · Physics 2009-02-12 R. Keith Ellis , W. T. Giele , Zoltan Kunszt , Kirill Melnikov , Giulia Zanderighi

We present a quantum algorithm for multiplying two $n$-bit integers with overall circuit depth and $T$-depth both bounded by $O(\log^{2} n)$, while using $O(n^{2})$ gates and ancillary qubits. Our construction generates partial products via…

Quantum Physics · Physics 2026-04-14 Fred Sun , Anton Borissov

We describe a general formalism based on the partial-wave decomposition to compute the iterative $s$-channel discontinuity of four-point amplitudes at any loop order. As an application, we focus on the low-energy expansions of type I and II…

High Energy Physics - Theory · Physics 2024-11-25 Yu-tin Huang , Hynek Paul , Michele Santagata

In this review we discuss some recent developments related to one-loop N = 4 super Yang-Mills scattering amplitudes calculated to all orders in epsilon. It is often the case that one-loop gauge theory computations are carried out to order…

High Energy Physics - Theory · Physics 2015-05-27 Robert M. Schabinger

An efficient method to calculate tadpole diagrams is proposed. Its capability is demonstrated by analytically evaluating two four-loop tadpole diagrams of current interest in the literature, including their $O(\epsilon)$ terms in…

High Energy Physics - Phenomenology · Physics 2009-11-11 Bernd A. Kniehl , Anatoly V. Kotikov

In these proceedings we report our progress in the development of the publicly available C++ library NJet for accurate calculations of high-multiplicity one-loop amplitudes. As a phenomenological application we present the first complete…

High Energy Physics - Phenomenology · Physics 2015-06-18 Simon Badger , Benedikt Biedermann , Peter Uwer , Valery Yundin

The well known Adler zero can fully determine tree amplitudes of non-linear sigma model (NLSM), but fails to fix tree pion amplitudes with higher-derivative interactions. To fill this gap, in this paper we propose a new method based on…

High Energy Physics - Theory · Physics 2026-05-05 Kang Zhou

Inspired by the calculational steps originally performed by Kawai, Lewellen and Tye, we decompose scattering amplitudes with single-valued coefficients obtained in the multi-Regge-limit of N=4 super-Yang-Mills theory into products of…

High Energy Physics - Theory · Physics 2023-06-29 Konstantin Baune , Johannes Broedel
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