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Using newly proposed BCF/BCFW recursion relations, compact formulas are obtained for tree-level n-gluon amplitudes of helicity structure --++...+. We then make an extension of these recursion relations to include fermions of multi-flavors,…

High Energy Physics - Theory · Physics 2008-11-26 Mingxing Luo , Congkao Wen

We demonstrate that all tree-level string theory amplitudes can be computed using the BCFW recursion relations. Our proof utilizes the pomeron vertex operator introduced by Brower, Polchinski, Strassler, and Tan. Surprisingly, we find that…

High Energy Physics - Theory · Physics 2014-11-20 Clifford Cheung , Donal O'Connell , Brian Wecht

This article provides an introduction to on-shell recursion relations for calculations of tree-level amplitudes. Starting with the basics, such as spinor notations and color decompositions, we expose analytic properties of gauge-boson…

High Energy Physics - Theory · Physics 2013-10-11 Bo Feng , Mingxing Luo

The fragmentation functions and scattering amplitudes are investigated in the framework of light-front perturbation theory. It is demonstrated that, the factorization property of the fragmentation functions implies the recursion relations…

High Energy Physics - Phenomenology · Physics 2015-06-16 Christian A. Cruz-Santiago , Anna M. Stasto

BCFW deformation has served as an extremely useful tool in providing a recursive approach in studying color-ordered gauge amplitudes. This procedure has also been generalized to the study of graviton scattering. An important ingredient of…

High Energy Physics - Theory · Physics 2013-06-03 Chih-Hao Fu , Jen-Chi Lee , Chung-I Tan , Yi Yang

We construct a modified on-shell BCFW recursion relation to derive compact analytic representations of tree-level amplitudes in QED. As an application, we study the amplitudes of a fermion pair coupling to an arbitrary number of photons and…

High Energy Physics - Phenomenology · Physics 2014-11-21 Simon Badger , Johannes M. Henn

In this paper, we explore the applicability of the BCFW-like recursion relations \cite{He:2018svj,Yang:2019esm} to a wider class of positive geometries. Previously it was found in \cite{Jagadale:2022rbl}, the tree level scattering amplitude…

High Energy Physics - Theory · Physics 2026-04-10 Sujoy Mahato , Sourav Roychowdhury

Britto, Cachazo and Feng have recently derived a recursion relation for tree-level scattering amplitudes in Yang-Mills. This relation has a bilinear structure inherited from factorisation on multi-particle poles of the scattering amplitudes…

High Energy Physics - Theory · Physics 2008-11-26 James Bedford , Andreas Brandhuber , Bill Spence , Gabriele Travaglini

We derive general tree-level recursion relations for amplitudes which include massive propagating particles. As an illustration, we apply these recursion relations to scattering amplitudes of gluons coupled to massive scalars. We provide…

High Energy Physics - Theory · Physics 2009-11-11 S. D. Badger , E. W. N. Glover , V. V. Khoze , P. Svrcek

Recently it has been shown that in gauge theories amplitudes to any perturbation order can be obtained by glueing together simple three-point on-shell amplitudes. These three-point amplitudes in turn are fixed by locality and Lorentz…

High Energy Physics - Phenomenology · Physics 2019-12-04 M. Maniatis

This paper investigates the relationships between closed and mixed string amplitudes at the tree level in string theory. Through the analytic continuation of complex variables, we establish a factorization of closed string amplitudes into…

High Energy Physics - Theory · Physics 2024-02-09 Aphiwat Yuenyong , Pongwit Srisangyingcharoen

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 show how to apply the BCFW recursion relation to Feynman loop integrals with the help of the Feynman-tree theorem. We deconstruct in this way all Feynman diagrams in terms of on-shell subamplitudes. Every cut originating from the…

High Energy Physics - Theory · Physics 2016-05-18 M. Maniatis , C. M. Reyes

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

This article studies methods to obtain relations for scattering amplitudes at the loop level, with concrete examples at one loop. These methods originate in the analysis of large so-called Britto-Cachazo-Feng-Witten shifts of tree level…

High Energy Physics - Theory · Physics 2015-05-30 Rutger H. Boels , Reinke Sven Isermann

We analyze the off-shell scattering amplitudes in the framework of the light-front perturbation theory. It is shown that the previously derived recursion relation between tree level off-shell amplitudes in this formalism actually resums…

High Energy Physics - Phenomenology · Physics 2015-06-24 C. Cruz-Santiago , P. Kotko , A. Stasto

We examine the BCFW recursion relations for celestial amplitudes and how they inform the celestial bootstrap program. We start by recasting the celestial incarnation of the BCFW shift as a generalization of the action of familiar asymptotic…

High Energy Physics - Theory · Physics 2023-01-31 Yangrui Hu , Sabrina Pasterski

We give closed form expressions for the numbers of multi-rooted plane trees with specified degrees of root vertices. This results in an infinite number of integer sequences some of which are known to have an alternative interpretation. We…

Combinatorics · Mathematics 2024-02-06 Anwar Al Ghabra , K. Gopala Krishna , Patrick Labelle , Vasilisa Shramchenko

We derive a general expression for on-shell recursion relations of closed string tree-level amplitudes. Starting with the string amplitudes written in the form of the Koba-Nielsen integral, we apply the BCFW shift to deform them. In…

High Energy Physics - Theory · Physics 2025-03-11 Pongwit Srisangyingcharoen , Aphiwat Yuenyong

In this paper, we study the tree amplitudes with gluons coupled to gravitons. We first study the relations among the mixed amplitudes. With BCFW on-shell recursion relation, we will show the color-order reversed relation, $U(1)$-decoupling…

High Energy Physics - Theory · Physics 2011-01-27 Yi-Xin Chen , Yi-Jian Du , Bo Feng