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380
New recursion relations for tree amplitudes of gluons
, 2004
"... We present new recursion relations for tree amplitudes in gauge theory that give very compact formulas. Our relations give any tree amplitude as a sum over terms constructed from products of two amplitudes of fewer particles multiplied by a Feynman propagator. The two amplitudes in each term are phy ..."
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Cited by 225 (9 self)
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We present new recursion relations for tree amplitudes in gauge theory that give very compact formulas. Our relations give any tree amplitude as a sum over terms constructed from products of two amplitudes of fewer particles multiplied by a Feynman propagator. The two amplitudes in each term are physical, in the sense that all particles are onshell and momentum conservation is preserved. This is striking, since is it just like adding certain factorization limits of the original amplitude to build up the full answer. As examples, we recompute all known treelevel amplitudes of up to seven gluons and show that our recursion relations naturally give their most compact forms. We give a new result for an eightgluon amplitude, A(1 +, 2 − , 3 +, 4 − , 5 +, 6 − , 7 +, 8 −). We show how to build any amplitude in terms of threegluon amplitudes only.
Yangian symmetry of scattering amplitudes
 in N = 4 super YangMills theory,” arXiv:0902.2987 [hepth
"... Treelevel scattering amplitudes in N = 4 super YangMills theory have recently been shown to transform covariantly with respect to a ‘dual ’ superconformal symmetry algebra, thus extending the conventional superconformal symmetry algebra psu(2,24) of the theory. In this paper we derive the action ..."
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Cited by 129 (15 self)
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Treelevel scattering amplitudes in N = 4 super YangMills theory have recently been shown to transform covariantly with respect to a ‘dual ’ superconformal symmetry algebra, thus extending the conventional superconformal symmetry algebra psu(2,24) of the theory. In this paper we derive the action of the dual superconformal generators in onshell superspace and extend the dual generators suitably to leave scattering amplitudes invariant. We then study the algebra of standard and dual symmetry generators and show that the inclusion of the dual superconformal generators lifts the psu(2,24) symmetry algebra to a Yangian. The nonlocal Yangian generators acting on amplitudes turn out to be cyclically invariant due to special properties of psu(2,24). The representation of the Yangian generators takes the same form as in the case of local operators, suggesting that the Yangian symmetry is The N = 4 supersymmetric YangMills theory (SYM) [1] is a remarkable model of mathematical physics. To begin with it is the gauge theory with maximal supersymmetry and it is superconformally invariant at the classical and quantum level with a coupling constant free of
An Alternative String Theory in Twistor Space for N=4 SuperYangMills,” arXiv:hepth/0402045
"... In this letter, an alternative string theory in twistor space is proposed for describing perturbative N=4 superYangMills theory. Like the recent proposal of Witten, this string theory uses twistor worldsheet variables and has manifest spacetime superconformal invariance. However, in this proposal, ..."
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Cited by 99 (3 self)
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In this letter, an alternative string theory in twistor space is proposed for describing perturbative N=4 superYangMills theory. Like the recent proposal of Witten, this string theory uses twistor worldsheet variables and has manifest spacetime superconformal invariance. However, in this proposal, treelevel superYangMills amplitudes come from open string tree amplitudes as opposed to coming from Dinstanton contributions.
Recursion relations for gauge theory amplitudes with massive particles
"... Preprint typeset in JHEP style PAPER VERSION hepth/0507161 ..."
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Cited by 51 (7 self)
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Preprint typeset in JHEP style PAPER VERSION hepth/0507161
A twistor approach to oneloop amplitudes in N = 1 SUPERSYMMETRIC YANGMILLS THEORY
, 2004
"... We extend the twistor string theory inspired formalism introduced in hepth/0407214 for calculating loop amplitudes in N =4 super YangMills theory to the case of N =1 (and N =2) super YangMills. Our approach yields a novel representation of the gauge theory amplitudes as dispersion integrals, whic ..."
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Cited by 46 (12 self)
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We extend the twistor string theory inspired formalism introduced in hepth/0407214 for calculating loop amplitudes in N =4 super YangMills theory to the case of N =1 (and N =2) super YangMills. Our approach yields a novel representation of the gauge theory amplitudes as dispersion integrals, which are surprisingly simple to evaluate. As an application we calculate oneloop maximally helicity violating (MHV) scattering amplitudes with an arbitrary number of external legs. The result we obtain agrees precisely with the expressions for the N = 1 MHV amplitudes derived previously by Bern, Dixon, Dunbar and Kosower using the cutconstructibility approach.
Hexagon Wilson loop = sixgluon MHV amplitude
, 2008
"... We compare the twoloop corrections to the finite part of the lightlike hexagon Wilson loop with the recent numerical results for the finite part of the MHV sixgluon amplitude in N = 4 SYM theory by Bern, Dixon, Kosower, Roiban, Spradlin, Vergu and Volovich (arXiv:0803.1465 [hepth]) and demonstra ..."
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Cited by 45 (5 self)
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We compare the twoloop corrections to the finite part of the lightlike hexagon Wilson loop with the recent numerical results for the finite part of the MHV sixgluon amplitude in N = 4 SYM theory by Bern, Dixon, Kosower, Roiban, Spradlin, Vergu and Volovich (arXiv:0803.1465 [hepth]) and demonstrate that they coincide within the error bars and, at the same time, they differ from the BDS ansatz by a nontrivial function of (dual) conformal kinematical invariants. This provides strong evidence that the Wilson loop/scattering amplitude duality holds in planar N = 4 SYM theory to all loops for an arbitrary number of external particles.
Cubic Twistorial String Field Theory,” JHEP 0404
, 2004
"... Abstract: Witten has recently proposed a string theory in twistor space whose Dinstanton contributions are conjectured to compute N = 4 superYangMills scattering amplitudes. An alternative string theory in twistor space was then proposed whose open string tree amplitudes reproduce the Dinstanton ..."
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Cited by 43 (1 self)
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Abstract: Witten has recently proposed a string theory in twistor space whose Dinstanton contributions are conjectured to compute N = 4 superYangMills scattering amplitudes. An alternative string theory in twistor space was then proposed whose open string tree amplitudes reproduce the Dinstanton computations of maximal degree in Witten’s model. In this paper, a cubic open string field theory action is constructed for this alternative string in twistor space, and is shown to be invariant under parity transformations which exchange MHV and googly amplitudes. Since the string field theory action is gaugeinvariant and reproduces the correct cubic superYangMills interactions, it provides strong support for the conjecture that the string theory correctly computes Npoint superYangMills tree amplitudes.