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We compute one-loop amplitudes in six-dimensional Yang-Mills theory with half-maximal supersymmetry from first principles: imposing gauge invariance and locality on an ansatz made from string-theory inspired kinematic building blocks yields…

High Energy Physics - Theory · Physics 2017-09-13 Marcus Berg , Igor Buchberger , Oliver Schlotterer

We study in detail the factorization of the newly obtained two-loop four-particle amplitude in superstring theory. In particular some missing factors from the scalar correlators are obtained correctly, in comparing with a previous study of…

High Energy Physics - Theory · Physics 2009-11-10 Zhi-Guang Xiao , Chuan-Jie Zhu

We show how to extract the coefficients of the 4-, 3-, 2- and 1-point one-loop scalar integrals from the full one-loop amplitude of arbitrary scattering processes. In a similar fashion, also the rational terms can be derived. Basically no…

High Energy Physics - Phenomenology · Physics 2008-11-26 Giovanni Ossola , Costas G. Papadopoulos , Roberto Pittau

We calculate form factors of half-BPS operators in N=4 super Yang-Mills theory at tree level and one loop using novel applications of recursion relations and unitarity. In particular, we determine the expression of the one-loop form factors…

High Energy Physics - Theory · Physics 2011-02-03 Andreas Brandhuber , Bill Spence , Gabriele Travaglini , Gang Yang

Recently, loop integrands for certain Yang-Mills scattering amplitudes and correlation functions have been shown to be systematically expressible in dlog form, raising the possibility that these loop integrals can be performed directly…

High Energy Physics - Theory · Physics 2015-06-16 Arthur E. Lipstein , Lionel Mason

All four-point mixed gluon-graviton amplitudes in pure Einstein-Yang-Mills theory with at most one state of negative helicity are computed at one-loop order and maximal powers of the gauge coupling using D-dimensional generalized unitarity.…

High Energy Physics - Theory · Physics 2018-09-26 Dhritiman Nandan , Jan Plefka , Gabriele Travaglini

In this talk we present techniques for calculating one-loop amplitudes for multi-leg processes using Feynman diagrammatic methods in a semi-algebraic context. Our approach combines the advantages of the different methods allowing for a fast…

In this paper, we give the general expressions for a special series of tree amplitudes of the Yang-Mills theory. This series of amplitudes have two adjacent massless spin-1 particles with extra-dimensional momenta and any number of positive…

High Energy Physics - Theory · Physics 2019-10-08 Yang An , Yi Li

The recently-developed "scalar-scaffolding" formulation of gluon amplitudes casts the Yang-Mills (YM) amplitude as a well-defined Laurent series expansion in scalar variables, valid for any spacetime dimension and helicity configuration. In…

High Energy Physics - Theory · Physics 2025-10-24 Jeffrey V. Backus

In this paper we discuss in detail computational methods and new results for one-loop virtual corrections to N = 4 super Yang-Mills scattering amplitudes calculated to all orders in epsilon, the dimensional regularization parameter. It is…

High Energy Physics - Theory · Physics 2015-03-19 Robert M. Schabinger

``Three-mass triangles'' are a class of integral functions appearing in one-loop gauge theory amplitudes. We discuss how the complex analytic properties and singularity structures of these amplitudes can be combined with generalised…

High Energy Physics - Phenomenology · Physics 2008-11-26 N. E. J. Bjerrum-Bohr , David C. Dunbar , Warren B. Perkins

We summarize recent progress in applying the worldline formalism to the analytic calculation of one-loop N-point amplitudes. This string-inspired approach is well-adapted to avoiding some of the calculational inefficiencies of the standard…

High Energy Physics - Theory · Physics 2022-05-18 James P. Edwards , C. Moctezuma Mata , Christian Schubert

We find a permutation relation among Yangian Invariants -- two Yangian Invariants with adjacent external lines exchanged are related by a simple kinematic factor. This relation is shown to be equivalent to U(1) decoupling and…

High Energy Physics - Theory · Physics 2016-01-18 Peizhi Du , Gang Chen , Yeuk-Kwan E. Cheung

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 thesis describes some of the recent (and some less recent) developments in calculational techniques for scattering amplitudes in quantum field theory. The focus is on on-shell recursion relations in complex momenta and on the use of…

High Energy Physics - Theory · Physics 2008-04-22 Kasper Risager

We discuss the calculation of one-loop amplitudes in N=8 supergravity using MHV diagrams. In contrast to MHV amplitudes of gluons in Yang-Mills, tree-level MHV amplitudes of gravitons are not holomorphic in the spinor variables. In order to…

High Energy Physics - Theory · Physics 2008-11-26 Adele Nasti , Gabriele Travaglini

One-loop amplitudes may be expanded in a basis of scalar integrals multiplied by rational coefficients. We relate the coefficient of the one-point integral to the coefficients of higher-point integrals, by considering the effects of…

High Energy Physics - Theory · Physics 2011-01-18 Ruth Britto , Bo Feng

We present an explicit formula for the n-point MHV one-loop amplitude in a N=4 supergravity theory. This formula is derived from the soft and collinear factorisations of the amplitude.

High Energy Physics - Theory · Physics 2015-06-03 David C. Dunbar , James H. Ettle , Warren B. Perkins

Soft and collinear factorisations can be used to construct expressions for amplitudes in theories of gravity. We generalise the "half-soft" functions used previously to "soft-lifting" functions and use these to generate tree and one-loop…

High Energy Physics - Theory · Physics 2013-05-30 David C. Dunbar , James H. Ettle , Warren B. Perkins

We study the S-matrix of planar $\mathcal{N}=4$ supersymmetric Yang-Mills theory when external momenta are restricted to a two-dimensional subspace of Minkowski space. We find significant simplifications and new, interesting structures for…

High Energy Physics - Theory · Physics 2015-06-15 Simon Caron-Huot , Song He