English
Related papers

Related papers: Calculating gluon one-loop amplitudes numerically

200 papers

We compute two infinite series of tree-level amplitudes with a massive scalar pair and an arbitrary number of gluons. We provide results for amplitudes where all gluons have identical helicity, and amplitudes with one gluon of opposite…

High Energy Physics - Theory · Physics 2009-11-11 Darren Forde , David A. Kosower

We show how the holomorphic anomaly found in hep-th/0409245 can be used to efficiently compute certain classes of unitarity cuts of one-loop N=4 amplitudes of gluons. These classes include all cuts of n-gluon one-loop MHV amplitudes and of…

High Energy Physics - Theory · Physics 2007-05-23 Freddy Cachazo

We show how generalised unitarity cuts in D = 4 - 2 epsilon dimensions can be used to calculate efficiently complete one-loop scattering amplitudes in non-supersymmetric Yang-Mills theory. This approach naturally generates the rational…

High Energy Physics - Theory · Physics 2009-11-11 Andreas Brandhuber , Simon McNamara , Bill Spence , Gabriele Travaglini

We discuss algebraic/numeric methods to compute one-loop corrections for multiparticle/jet production cross sections. By using efficient reduction algorithms a compact expression for the ggg\gamma\gamma -> 0 amplitude is obtained. Further a…

High Energy Physics - Phenomenology · Physics 2009-11-10 T. Binoth

We review the recently developed bootstrap method for the computation of high-multiplicity QCD amplitudes at one loop. We illustrate the general algorithm step by step with a six-point example. The method combines (generalized) unitarity…

High Energy Physics - Phenomenology · Physics 2008-11-26 Carola F. Berger

We present a new method for computing complete one-loop amplitudes, including their rational parts, in non-supersymmetric gauge theory. This method merges the unitarity method with on-shell recursion relations. It systematizes a…

High Energy Physics - Phenomenology · Physics 2010-11-15 Zvi Bern , Lance J. Dixon , David A. Kosower

This article brings together in a single place the different components of the six gluon one-loop amplitude

High Energy Physics - Phenomenology · Physics 2009-01-12 David C Dunbar

We use twistor inspired rules to compute the one-loop amplitude for a Higgs boson coupling to any number of negative helicity gluons in the large top mass limit.

High Energy Physics - Phenomenology · Physics 2008-11-26 S. D. Badger , E. W. N. Glover

A powerful tool for calculations in non-Abelian gauge theories is obtained by combining the background field gauge, the helicity basis and the color decomposition methods. It has reproduced the one-loop calculation of the five-gluon…

High Energy Physics - Phenomenology · Physics 2009-10-31 Yoshiaki Yasui

We show that one-loop amplitudes in massless gauge theories can be determined from single cuts. By cutting a single propagator and putting it on-shell, the integrand of an n-point one-loop integral is transformed into an (n+2)-particle tree…

High Energy Physics - Theory · Physics 2008-12-25 E. W. Nigel Glover , Ciaran Williams

We present a semi-recursive method for calculating the rational parts of one-loop amplitudes when recursion produces double poles. We illustrate this with the graviton scattering amplitude M^{1-loop}(1-, 2+, 3+, 4+, 5+).

High Energy Physics - Theory · Physics 2010-12-13 David C. Dunbar , James H. Ettle , Warren B. Perkins

We compute the complete one-loop corrections to the simplest class of QCD gluon amplitudes, those with two color-adjacent opposite-helicity external particles. We present results for an arbitrary number of external legs. The computation…

High Energy Physics - Phenomenology · Physics 2009-11-11 Darren Forde , David A. Kosower

A numerical program is presented which facilitates the computation of the full set of one-gluon loop diagrams (including ghost loop contributions), with M attached external gluon lines in all possible ways. The feasibility of such a task…

High Energy Physics - Theory · Physics 2007-05-23 A. S. Kapoyannis , A. I. Karanikas , C. N. Ktorides

Techniques based upon the string organisation of amplitudes may be used to simplify field theory calculations. We apply these techniques to perturbative gravity and calculate all one-loop amplitudes for four-graviton scattering with…

High Energy Physics - Theory · Physics 2009-10-28 David C. Dunbar , Paul S. Norridge

We present the first results from BlackHat, an automated C++ program for calculating one-loop amplitudes. The program implements the unitarity method and on-shell recursion to construct amplitudes. As input to the calculation, it uses…

High Energy Physics - Phenomenology · Physics 2008-11-26 C. F. Berger , Z. Bern , L. J. Dixon , F. Febres Cordero , D. Forde , H. Ita , D. A. Kosower , D. Maitre

Using CSW rules for constructing scalar Feynman diagrams from MHV vertices, we compute the contribution of $\mathcal {N}=1$ chiral multiplet to one-loop MHV gluon amplitude. The result agrees with the one obtained previously using…

High Energy Physics - Theory · Physics 2009-11-10 Callum Quigley , Moshe Rozali

We present a semi-recursive method for calculating the rational parts of one-loop gravity amplitudes which utilises axial gauge diagrams to determine the non-factorising pieces of the amplitude. This method is used to compute the one-loop…

High Energy Physics - Theory · Physics 2014-11-20 David C. Dunbar , James H. Ettle , Warren B. Perkins

A precise understanding of LHC phenomenology requires the inclusion of one-loop corrections for multi-particle final states. In this talk we describe a semi-numerical method to compute one-loop amplitudes with many external particles and…

High Energy Physics - Phenomenology · Physics 2009-11-11 T. Binoth , M. Ciccolini , G. Heinrich

We show, for previously uncalculated examples containing a uniform mass in the loop, that it is possible to obtain complete massive one-loop gauge theory amplitudes solely from unitarity and known ultraviolet or infrared mass singularities.…

High Energy Physics - Phenomenology · Physics 2008-11-26 Z. Bern , A. G. Morgan

We present an algorithm for the numerical calculation of one-loop QCD amplitudes. The algorithm consists of subtraction terms, approximating the soft, collinear and ultraviolet divergences of one-loop amplitudes and a method to deform the…

High Energy Physics - Phenomenology · Physics 2010-12-09 Sebastian Becker , Christian Reuschle , Stefan Weinzierl