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Related papers: Multi-gluon one-loop amplitudes numerically

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We discuss new results in QCD obtained with string-based methods. These methods were originally derived from superstring theory and are significantly more efficient than conventional Feynman rules. This technology was a key ingredient in…

High Energy Physics - Theory · Physics 2007-05-23 Z. Bern , L. Dixon , D. A. Kosower

Using the method of on-shell recursion relations we compute tree level amplitudes including D-dimensional scalars and fermions. These tree level amplitudes are needed for calculations of one-loop amplitudes in QCD involving external quarks…

High Energy Physics - Phenomenology · Physics 2009-11-11 Callum Quigley , Moshe Rozali

We compute the one-loop QCD amplitudes for the decay of an off-shell vector boson with vector couplings into a quark-antiquark pair accompanied by two gluons keeping, for the first time, all orders in the number of colours. Together with…

High Energy Physics - Phenomenology · Physics 2008-11-26 J. M. Campbell , E. W. N. Glover , D. J. Miller

We present an analytic expression for the six-point all-plus helicity amplitude in QCD at two-loops. We compute the rational terms in a compact analytic form organised by their singularity structure.

High Energy Physics - Theory · Physics 2016-08-10 David C. Dunbar , Warren B. Perkins

We report on the calculation of virtual processes contributing to the production of a Higgs boson and two jets in hadron-hadron collisions. The coupling of the Higgs boson to gluons, via a virtual loop of top quarks, is treated using an…

High Energy Physics - Phenomenology · Physics 2014-11-18 R. K. Ellis , W. T. Giele , G. Zanderighi

It is well known that under the color-decomposition, one-loop amplitude of gluons contains partial amplitudes of single and double trace structures, and particularly all partial amplitudes of double trace structure can be expressed as a…

High Energy Physics - Phenomenology · Physics 2015-05-28 Bo Feng , Yin Jia , Rijun Huang

We compute the next-to-MHV one-loop n-gluon amplitudes in N=4 super-Yang-Mills theory. These amplitudes contain three negative-helicity gluons and an arbitrary number of positive-helicity gluons, and are the first infinite series of…

High Energy Physics - Theory · Physics 2010-04-06 Zvi Bern , Lance J. Dixon , David A. Kosower

We present the two-loop amplitudes for a self-dual Higgs boson with up to four positive helicity gluons in the heavy top-quark limit. Because the tree amplitudes in the all-plus sector vanish, we can construct simple representations of the…

High Energy Physics - Phenomenology · Physics 2026-05-15 Simon Badger , Christian Biello , Colomba Brancaccio , Federico Ripani

A method to define and calculate one-loop amplitudes with an off-shell space-like, or $k_T$-dependent, gluon is presented. It introduces a practical regularization to deal with the divergencies that appear due to linear denominators, and…

High Energy Physics - Phenomenology · Physics 2022-02-01 A. van Hameren

After reduction techniques, two-loop amplitudes in N=4 super Yang-Mills theory can be written in a basis of integrals containing scalar double-box integrals with rational coefficients, though the complete basis is unknown. Generically, at…

High Energy Physics - Theory · Physics 2009-11-11 Evgeny I. Buchbinder , Freddy Cachazo

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

We consider a Higgs boson coupled to gluons via the five-dimensional effective operator H tr G_{\mu\nu}G^{\mu\nu}. We treat H as the real part of a complex field phi that couples to the selfdual gluon field strengths and compute the…

High Energy Physics - Phenomenology · Physics 2009-02-09 E. W. N. Glover , Pierpaolo Mastrolia , Ciaran Williams

The factorisation of QCD matrix elements in the limit of two external partons becoming collinear is described by process-independent splitting amplitudes, which can be expanded systematically in perturbation theory. Working in conventional…

High Energy Physics - Phenomenology · Physics 2015-06-23 Claude Duhr , Thomas Gehrmann , Matthieu Jaquier

In this paper, we give the general expressions for a special series of tree amplitudes of the Yang-Mills theory. This series of amplitudes have two adjacent massless spin-1 particles with extra-dimensional momenta and any number of positive…

High Energy Physics - Theory · Physics 2019-10-08 Yang An , Yi Li

We show that the chiral algebra bootstrap, which computes form factors of twistorial theories, can help determine two-loop amplitudes in massless QCD. We give an $n$-gluon result for a previously unknown partial amplitude of the two-loop…

High Energy Physics - Theory · Physics 2025-10-24 Anthony Morales

I present results for the resummation of soft and collinear gluon contributions to QCD hard-scattering cross sections at two loops. This requires the calculation of UV and IR divergences through two loops and the construction of soft…

High Energy Physics - Phenomenology · Physics 2010-11-19 Nikolaos Kidonakis

We report a state-of-the-art lattice QCD calculation of the nucleon gluon parton distribution function employing large-momentum effective theory. The calculation is carried out on the 2+1 flavour CLQCD ensembles with three lattice spacings…

High Energy Physics - Lattice · Physics 2025-10-31 Chen Chen , Hongxin Dong , Liuming Liu , Peng Sun , Xiaonu Xiong , Yi-Bo Yang , Fei Yao , Jian-Hui Zhang , Chunhua Zeng , Shiyi Zhong

This contribution presents the running triple-gluon-vertex coupling constant, g_lambda, in Hamiltonians for the gluons that are characterized by the size 1/lambda. The coupling constant is obtained from renormalization group equations for…

High Energy Physics - Theory · Physics 2017-08-23 Stanislaw D. Glazek

In this thesis, we present recent advances at the precision frontier of higher-order quantum chromodynamics (QCD) calculations. We consider massless two-loop five-point amplitudes, with a particular focus on diphoton-plus-jet production…

High Energy Physics - Phenomenology · Physics 2022-10-14 Ryan Moodie

We prove that all tree-level $n$-point supergluon (scalar) amplitudes in AdS$_5$ can be recursively constructed, using factorization and flat-space limit. Our method is greatly facilitated by a natural R-symmetry basis for planar…

High Energy Physics - Theory · Physics 2025-08-12 Qu Cao , Song He , Yichao Tang