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Related papers: Tree-level Split Helicity Amplitudes in Ambitwisto…

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Using recursion methods similar to those of Britto, Cachazo, Feng and Witten (BCFW) a direct proof of the CSW rules for computing tree-level gluon amplitudes is given.

High Energy Physics - Theory · Physics 2010-02-03 Kasper Risager

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

Following~\cite{Arkani-Hamed:2017thz}, we derive a recursion relation by applying a one-parameter deformation of kinematic variables for tree-level scattering amplitudes in bi-adjoint $\phi^3$ theory. The recursion relies on properties of…

High Energy Physics - Theory · Physics 2019-05-28 Song He , Qinglin Yang

We study in detail the general structure and further properties of the tree-level amplitudes in the SU(N) nonlinear sigma model. We construct the flavor-ordered Feynman rules for various parameterizations of the SU(N) fields U(x), write…

High Energy Physics - Theory · Physics 2015-06-15 Karol Kampf , Jiri Novotny , Jaroslav Trnka

We consider multi-parton collinear limits of QCD amplitudes at tree level. Using the MHV formalism we specify the underlying analytic structure of the resulting multi-collinear splitting functions. We derive general results for these…

High Energy Physics - Phenomenology · Physics 2009-11-11 T. G. Birthwright , E. W. N. Glover , V. V. Khoze , P. Marquard

We derive compact analytical formulae for all tree-level color-ordered gauge theory amplitudes involving any number of external gluons and up to three massless quark-anti-quark pairs. A general formula is presented based on the…

High Energy Physics - Phenomenology · Physics 2011-01-24 Lance J. Dixon , Johannes M. Henn , Jan Plefka , Theodor Schuster

Using twistor space intuition, Cachazo, Svrcek and Witten presented novel diagrammatic rules for gauge-theory amplitudes, expressed in terms of maximally helicity-violating (MHV) vertices. We define non-MHV vertices, and show how to use…

High Energy Physics - Theory · Physics 2009-11-10 I. Bena , Z. Bern , D. A. Kosower

We use tree-level perturbation theory to show how non-supersymmetric one-loop scattering amplitudes for a Higgs boson plus an arbitrary number of partons can be constructed, in the limit of a heavy top quark, from a generalization of the…

High Energy Physics - Theory · Physics 2010-04-06 Lance J. Dixon , E. W. N. Glover , Valentin V. Khoze

We use the twistor-string theory on the B-model of CP^{3|4} to compute the maximally helicity violating(MHV) tree amplitudes for conformal supergravitons. The correlator of a bilinear in the affine Kac-Moody current(Sugawara stress-energy…

High Energy Physics - Theory · Physics 2010-02-03 Changhyun Ahn

The recursive method of Berends and Giele to compute tree-level gluon amplitudes is revisited using the framework of ten-dimensional super Yang-Mills. First we prove that the pure spinor formula to compute SYM tree amplitudes derived in…

High Energy Physics - Theory · Physics 2016-04-12 Carlos R. Mafra , Oliver Schlotterer

We use on-shell recursion relations to compute analytically the one-loop corrections to maximally-helicity-violating n-gluon amplitudes in QCD. The cut-containing parts have been computed previously; our work supplies the remaining rational…

High Energy Physics - Phenomenology · Physics 2008-11-26 Carola F. Berger , Zvi Bern , Lance J. Dixon , Darren Forde , David A. Kosower

In this paper, we present a systematic derivation aimed at obtaining general expressions for on-shell recursion relations for tree-level open string amplitudes. Our approach involves applying the BCFW shift to an open string amplitude…

High Energy Physics - Theory · Physics 2024-04-02 Pongwit Srisangyingcharoen

In planar N=4 SYM we study a particular class of helicity preserving amplitudes. These are scalar amplitudes whose flavor configuration is chosen in such a way that only a limited number of diagrams is allowed, which exhibit an iterative…

High Energy Physics - Theory · Physics 2015-06-11 Marco S. Bianchi , Matias Leoni , Silvia Penati

We derive an on-shell diagram recursion for tree-level scattering amplitudes in $\mathcal{N}=7$ supergravity. The diagrams are evaluated in terms of Grassmannian integrals and momentum twistors, generalising previous results of Hodges in…

High Energy Physics - Theory · Physics 2021-05-12 Connor Armstrong , Joseph A. Farrow , Arthur E. Lipstein

Using the novel diagrammatic rules recently proposed by Cachazo, Svrcek, and Witten, I give a compact, manifestly Lorentz-invariant form for tree-level gauge-theory amplitudes with three opposite helicities.

High Energy Physics - Theory · Physics 2009-11-10 David A. Kosower

This article proves the cyclicity of anti-NMHV and N$^2$MHV tree amplitudes in planar N=4 SYM up to any number of external particles as an interesting application of positive Grassmannian geometry. In this proof the two-fold simplex-like…

High Energy Physics - Theory · Physics 2020-06-23 Junjie Rao

In AdS/CFT, we introduce a robust method for computing $n$-point gluon Mellin amplitudes, applicable in various spacetime dimensions. Using the Mellin transform and a recursive algorithm, we efficiently calculate tree-level gluon…

High Energy Physics - Theory · Physics 2023-11-14 Jinwei Chu , Savan Kharel

We extend the argument presented by Benincasa, Boucher-Veronneau, and Cachazo to show that graviton tree amplitudes are well behaved under large complex deformations of the momenta of a pair of like-helicity gravitons. This shows that BCFW…

High Energy Physics - Theory · Physics 2008-11-26 Anthony Hall

We consider a Higgs boson coupled to gluons via the five-dimensional effective operator H Tr G_{munu}G^{munu} produced by considering the heavy top quark limit of the one-loop coupling of Higgs and gluons in the standard model. We treat H…

High Energy Physics - Phenomenology · Physics 2009-04-21 S. D. Badger , E. W. N. Glover , Kasper Risager

We prove that the MHV vertex expansion is valid for any NMHV tree amplitude of N=4 SYM. The proof uses induction to show that there always exists a complex deformation of three external momenta such that the amplitude falls off at least as…

High Energy Physics - Theory · Physics 2009-04-17 Henriette Elvang , Daniel Z. Freedman , Michael Kiermaier