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Higher order calculations in perturbative Quantum Field Theories often produce coupled linear systems of differential equations which factorize to first order. Here we present an algorithm to solve such systems in terms of iterated…

High Energy Physics - Phenomenology · Physics 2020-08-26 J. Ablinger , J. Blümlein , P. Marquard , N. Rana , C. Schneider

We propose a quantum algorithm for computing the n-gluon maximally helicity violating (MHV) tree-level scattering amplitude. We revisit a newly proposed method for unitarisation of non-unitary operations and present how this implementation…

High Energy Physics - Phenomenology · Physics 2026-04-17 Erik Bashore , Stefano Moretti , Timea Vitos

We present a method for the computation of hepta-cuts of two loop scattering amplitudes. Four dimensional unitarity cuts are used to factorise the integrand onto the product of six tree-level amplitudes evaluated at complex momentum values.…

High Energy Physics - Phenomenology · Physics 2012-04-18 Simon Badger , Hjalte Frellesvig , Yang Zhang

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 study the soft limit of one-loop QCD amplitudes and we derive the process-independent factorization formula that controls the singular behaviour in this limit. This is obtained from the customary eikonal factorization formula valid at…

High Energy Physics - Phenomenology · Physics 2009-10-31 S. Catani , M. Grazzini

We present first calculations of QCD matrix-elements in perturbation theory at finite Nc beyond 2 loops in the eikonal approximation for e+ e- annihilation processes. For the emission of n soft energy-ordered gluons we solve both the colour…

High Energy Physics - Phenomenology · Physics 2015-07-07 Kamel Khelifa-Kerfa , Yazid Delenda

The success of the experimental program at the Tevatron re-inforced the idea that precision physics at hadron colliders is desirable and, indeed, possible. The Tevatron data strongly suggests that one-loop computations in QCD describe hard…

High Energy Physics - Phenomenology · Physics 2015-05-28 R. Keith Ellis , Zoltan Kunszt , Kirill Melnikov , Giulia Zanderighi

I describe a method for determining the coefficients of scalar integrals for one-loop amplitudes in quantum field theory. The method is based upon generalized unitarity and the behavior of amplitudes when the free parameters of the cut…

High Energy Physics - Phenomenology · Physics 2008-05-12 William B. Kilgore

Quantum computers are expected to give major speed-ups for the simulation of quantum systems. In these conference proceedings, we discuss quantum algorithms for the simulation of perturbative Quantum Chromodynamics (QCD) processes. In…

High Energy Physics - Phenomenology · Physics 2023-09-14 Herschel A. Chawdhry , Mathieu Pellen

We present a computer library for the numerical evaluation of colour-ordered n-gluon amplitudes at one-loop order in pure Yang-Mills theory. The library uses the recently developed technique of generalised unitarity. Running in double…

High Energy Physics - Phenomenology · Physics 2013-03-05 Simon Badger , Benedikt Biedermann , Peter Uwer

A summary is presented of the most recent matrix elements for massless 2 to 2 scattering processes calculated at two loops in QCD perturbation theory together with a brief review on the calculational methods and techniques used.

High Energy Physics - Phenomenology · Physics 2009-11-07 Maria Elena Tejeda-Yeomans

We present a set of relations between one-loop integral coefficients for dimensionally regulated QCD amplitudes. Within dimensional regularization, the combined use of color-kinematics duality and integrand reduction yields the existence of…

High Energy Physics - Phenomenology · Physics 2016-05-25 Amedeo Primo , William J. Torres Bobadilla

An overview is presented on the current status of main mathematical computation methods for the multi-loop corrections to single scale observables in quantum field theory and the associated mathematical number and function spaces and…

High Energy Physics - Phenomenology · Physics 2018-09-19 Johannes Blümlein , Carsten Schneider

We present analytic results for the one-loop corrections of the helicity amplitudes of the QCD five-parton subprocesses involving four quarks and one gluon obtained with a standard Feynman diagram calculation using dimensional reduction.

High Energy Physics - Phenomenology · Physics 2009-10-28 Zoltan Kunszt , Adrian Signer , Zoltan Trocsanyi

The quantum inverse scattering method is applied to the solution of equations for wave functions of compound states of $n$ reggeized gluons in the multicolour QCD in a generalized leading logarithmic approximation.

High Energy Physics - Theory · Physics 2007-05-23 L. N. Lipatov

In this paper, we present an extension of MadGraph5_aMC@NLO which is able to evaluate tree-level QCD matrix-elements up to $2\to 6$ (one more particle than before). To achieve this, we implemented Berends-Giele-like recursion, and…

High Energy Physics - Phenomenology · Physics 2022-12-20 Andrew Lifson , Olivier Mattelaer

We calculate the four-loop massless QCD corrections with three closed quark lines to quark and gluon form factors. We apply a novel integration by parts algorithm based on modular arithmetic and compute all relevant master integrals for…

High Energy Physics - Phenomenology · Physics 2017-03-01 Andreas von Manteuffel , Robert M. Schabinger

We present a semi-numerical method to compute one-loop corrections to multi-leg processes. We apply the method to the study of Higgs plus four parton and six gluon amplitudes.

High Energy Physics - Phenomenology · Physics 2007-05-23 G. Zanderighi

We review the current state-of-the-art in integrand level reduction for five-point scattering amplitudes at two loops in QCD. We present some benchmark results for the evaluation of the leading colour two-loop five-gluon amplitudes in the…

Quantum computers are expected to give major speed-ups for the simulation of quantum systems. In this work, we present quantum gates that simulate the colour part of the interactions of quarks and gluons in perturbative quantum…

High Energy Physics - Phenomenology · Physics 2023-12-04 Herschel A. Chawdhry , Mathieu Pellen