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Related papers: Pfaffian Diagrams for Gluon Tree Amplitudes

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We compute tree-level $n$-point scattering amplitudes in scalar field theories in terms of geometric invariants on a fibre bundle. All 0- and 2-derivative interactions are incorporated into a metric on this bundle. The on-shell amplitudes…

High Energy Physics - Theory · Physics 2025-09-26 Mohammad Alminawi , Ilaria Brivio , Joe Davighi

We pick up a method originally developed by Cheng and Tsai for vacuum perturbation theory which allows to test the consistency of different sets of Feynman rules on a purely diagrammatic level, making explicit loop calculations superfluous.…

High Energy Physics - Theory · Physics 2009-10-09 Marc Achhammer , Ulrich Heinz , Stefan Leupold , Urs Achim Wiedemann

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

We present algorithms for the group independent reduction of group theory factors of Feynman diagrams. We also give formulas and values for a large number of group invariants in which the group theory factors are expressed. This includes…

High Energy Physics - Phenomenology · Physics 2008-11-26 T. van Ritbergen , A. N. Schellekens , J. A. M. Vermaseren

We calculate on-shell scattering amplitudes involving fermions at the tree level in open superstring field theory. We confirm that four-point and five-point amplitudes in the world-sheet path integral with the standard prescription using…

High Energy Physics - Theory · Physics 2016-12-05 Hiroshi Kunitomo , Yuji Okawa , Hiroki Sukeno , Tomoyuki Takezaki

We prove that all tree-level amplitudes in pure (super-)gravity can be expressed as term-wise, gauge-invariant double-copies of those of pure (super-)Yang-Mills obtained via BCFW recursion. These representations are far from unique: varying…

High Energy Physics - Theory · Physics 2023-07-07 Jacob L. Bourjaily , Nikhil Kalyanapuram , Kokkimidis Patatoukos , Michael Plesser , Yaqi Zhang

In this article we review, for a mathematical audience, the computation of (tree-level) scattering amplitudes in Yang-Mills theory in detail, in order to bridge the gap in understanding of the subject between mathematicians and physicists.…

High Energy Physics - Theory · Physics 2025-07-25 Shounak De , Dmitrii Pavlov , Marcus Spradlin , Anastasia Volovich

A method is developed whereby spinor helicity techniques can be used to simplify the calculation of loop amplitudes. This is achieved by using the Feynman-parameter representation where the offending off-shell loop momenta do not appear.…

High Energy Physics - Phenomenology · Physics 2009-10-22 C. S. Lam

A unified treatment of Schwinger parametrised Feynman amplitudes is suggested which addresses vertices of arbitrary order on the same footing as propagators. Contributions from distinct diagrams are organised collectively. The scheme is…

High Energy Physics - Theory · Physics 2014-11-18 Helmut Hölzler

We describe the implementation and usage of `fermionic_amplitudes.m', a Mathematica package for the computation of tree amplitudes involving arbitrary numbers of gauge bosons and arbitrarily-charged massless fermions of (possibly) distinct…

High Energy Physics - Theory · Physics 2026-04-22 Jacob L. Bourjaily , Michael Plesser , Philip Velie

In a way analogous to type IIB supergravity, we give a covariant action for the fermion field supplemented with a constraint which should be imposed on equations of motion, in Berkovits' open superstring field theory. From this action we…

High Energy Physics - Theory · Physics 2010-02-03 Yoji Michishita

We elaborate on the connection between Gel'fand-Kapranov-Zelevinsky systems, de Rham theory for twisted cohomology groups, and Pfaffian equations for Feynman integrals. We propose a novel, more efficient algorithm to compute Macaulay…

We present a new formulation for Yang-Mills scattering amplitudes in any number of dimensions and at any loop order, based on the same combinatorial and binary-geometric ideas in kinematic space recently used to give an all-order…

High Energy Physics - Theory · Physics 2025-05-02 Nima Arkani-Hamed , Qu Cao , Jin Dong , Carolina Figueiredo , Song He

Planar arrays of tree diagrams were introduced as a generalization of Feynman diagrams that enables the computation biadjoint amplitudes $m^{(k)}_n$ for $k>2$ . In this follow-up work we investigate the poles of $m^{(k)}_n$ from the…

High Energy Physics - Theory · Physics 2024-03-27 Alfredo Guevara , Yong Zhang

Recently, we proposed a new approach for calculating Feynman graphs amplitude using the Gaussian representation for propagators which was proven to be exact in the limit of graphs having an infinite number of loops. Regge behavior was also…

High Energy Physics - Phenomenology · Physics 2015-06-25 Richard Hong Tuan

We demonstrate that the tree level amplitudes and the explicit formulas of soft factors can be uniquely determined by soft theorems and the universality of soft factors. By imposing the soft theorems and the universality, as well as the…

High Energy Physics - Theory · Physics 2026-05-05 Kang Zhou

We present a general algorithm to compute off-shell, one-loop multigluon Green functions using bosonic string amplitudes. We identify and parametrize the regions in the space of moduli of one-loop Riemann surfaces that contribute to the…

High Energy Physics - Phenomenology · Physics 2009-10-31 Alberto Frizzo , Lorenzo Magnea , Rodolfo Russo

As an alternative to the usual Feynman graphs, tree amplitudes in Yang-Mills theory can be constructed from tree graphs in which the vertices are tree level MHV scattering amplitudes, continued off shell in a particular fashion. The…

High Energy Physics - Theory · Physics 2010-04-07 Freddy Cachazo , Peter Svrcek , Edward Witten

Up until now, the BCFW technique has been a widely used method in getting the amplitudes in various theories. Usually, the vanishing of the boundary term is necessary for the efficiency of the method. However, there are also many kinds of…

High Energy Physics - Theory · Physics 2012-04-06 Gang Chen

Scattering amplitudes in Yang-Mills theory can be represented in the formalism of Cachazo, He and Yuan (CHY) as integrals over an auxiliary projective space---fully localized on the support of the scattering equations. Because solving the…

High Energy Physics - Theory · Physics 2016-12-21 N. E. J. Bjerrum-Bohr , Jacob L. Bourjaily , Poul H. Damgaard , Bo Feng