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Amplitudes
The Experts below are selected from a list of 288 Experts worldwide ranked by ideXlab platform
Zvi Bern – 1st expert on this subject based on the ideXlab platform

iteration of planar Amplitudes in maximally supersymmetric yang mills theory at three loops and beyond
Physical Review D, 2005CoAuthors: Zvi Bern, Lance J Dixon, V SmirnovAbstract:We compute the leadingcolor (planar) threeloop fourpoint amplitude of N = 4 supersymmetric YangMills theory in 4 – 2{epsilon} dimensions, as a Laurent expansion about {epsilon} = 0 including the finite terms. The amplitude was constructed previously via the unitarity method, in terms of two Feynman loop integrals, one of which has been evaluated already. Here we use the MellinBarnes integration technique to evaluate the Laurent expansion of the second integral. Strikingly, the amplitude is expressible, through the finite terms, in terms of the corresponding one and twoloop Amplitudes, which provides strong evidence for a previous conjecture that higherloop planar N = 4 Amplitudes have an iterative structure. The infrared singularities of the amplitude agree with the predictions of Sterman and TejedaYeomans based on resummation. Based on the fourpoint result and the exponentiation of infrared singularities, we give an exponentiated ansatz for the maximally helicityviolating npoint Amplitudes to all loop orders. The 1/{epsilon}{sup 2} pole in the fourpoint amplitude determines the soft, or cusp, anomalous dimension at three loops in N = 4 supersymmetric YangMills theory. The result confirms a prediction by Kotikov, Lipatov, Onishchenko and Velizhanin, which utilizes the leadingtwist anomalous dimensions in QCD computed by Moch, Vermaseren and Vogt. Following similar logic, we are able to predict a term in the threeloop quark and gluon form factors in QCD.

planar Amplitudes in maximally supersymmetric yang mills theory
Physical Review Letters, 2003CoAuthors: Charalampos Anastasiou, Zvi Bern, Lance J Dixon, D A KosowerAbstract:The collinear factorization properties of twoloop scattering Amplitudes in dimensionallyregulated N = 4 superYangMills theory suggest that, in the planar (‘t Hooft) limit, higherloop contributions can be expressed entirely in terms of oneloop Amplitudes. We demonstrate this relation explicitly for the twoloop fourpoint amplitude and, based on the collinear limits, conjecture an analogous relation for npoint Amplitudes. The simplicity of the relation is consistent with intuition based on the AdS/CFT correspondence that the form of the large N{sub c} Lloop Amplitudes should be simple enough to allow a resummation to all orders.
V Smirnov – 2nd expert on this subject based on the ideXlab platform

iteration of planar Amplitudes in maximally supersymmetric yang mills theory at three loops and beyond
Physical Review D, 2005CoAuthors: Zvi Bern, Lance J Dixon, V SmirnovAbstract:We compute the leadingcolor (planar) threeloop fourpoint amplitude of N = 4 supersymmetric YangMills theory in 4 – 2{epsilon} dimensions, as a Laurent expansion about {epsilon} = 0 including the finite terms. The amplitude was constructed previously via the unitarity method, in terms of two Feynman loop integrals, one of which has been evaluated already. Here we use the MellinBarnes integration technique to evaluate the Laurent expansion of the second integral. Strikingly, the amplitude is expressible, through the finite terms, in terms of the corresponding one and twoloop Amplitudes, which provides strong evidence for a previous conjecture that higherloop planar N = 4 Amplitudes have an iterative structure. The infrared singularities of the amplitude agree with the predictions of Sterman and TejedaYeomans based on resummation. Based on the fourpoint result and the exponentiation of infrared singularities, we give an exponentiated ansatz for the maximally helicityviolating npoint Amplitudes to all loop orders. The 1/{epsilon}{sup 2} pole in the fourpoint amplitude determines the soft, or cusp, anomalous dimension at three loops in N = 4 supersymmetric YangMills theory. The result confirms a prediction by Kotikov, Lipatov, Onishchenko and Velizhanin, which utilizes the leadingtwist anomalous dimensions in QCD computed by Moch, Vermaseren and Vogt. Following similar logic, we are able to predict a term in the threeloop quark and gluon form factors in QCD.
Lance J Dixon – 3rd expert on this subject based on the ideXlab platform

iteration of planar Amplitudes in maximally supersymmetric yang mills theory at three loops and beyond
Physical Review D, 2005CoAuthors: Zvi Bern, Lance J Dixon, V SmirnovAbstract:We compute the leadingcolor (planar) threeloop fourpoint amplitude of N = 4 supersymmetric YangMills theory in 4 – 2{epsilon} dimensions, as a Laurent expansion about {epsilon} = 0 including the finite terms. The amplitude was constructed previously via the unitarity method, in terms of two Feynman loop integrals, one of which has been evaluated already. Here we use the MellinBarnes integration technique to evaluate the Laurent expansion of the second integral. Strikingly, the amplitude is expressible, through the finite terms, in terms of the corresponding one and twoloop Amplitudes, which provides strong evidence for a previous conjecture that higherloop planar N = 4 Amplitudes have an iterative structure. The infrared singularities of the amplitude agree with the predictions of Sterman and TejedaYeomans based on resummation. Based on the fourpoint result and the exponentiation of infrared singularities, we give an exponentiated ansatz for the maximally helicityviolating npoint Amplitudes to all loop orders. The 1/{epsilon}{sup 2} pole in the fourpoint amplitude determines the soft, or cusp, anomalous dimension at three loops in N = 4 supersymmetric YangMills theory. The result confirms a prediction by Kotikov, Lipatov, Onishchenko and Velizhanin, which utilizes the leadingtwist anomalous dimensions in QCD computed by Moch, Vermaseren and Vogt. Following similar logic, we are able to predict a term in the threeloop quark and gluon form factors in QCD.

planar Amplitudes in maximally supersymmetric yang mills theory
Physical Review Letters, 2003CoAuthors: Charalampos Anastasiou, Zvi Bern, Lance J Dixon, D A KosowerAbstract:The collinear factorization properties of twoloop scattering Amplitudes in dimensionallyregulated N = 4 superYangMills theory suggest that, in the planar (‘t Hooft) limit, higherloop contributions can be expressed entirely in terms of oneloop Amplitudes. We demonstrate this relation explicitly for the twoloop fourpoint amplitude and, based on the collinear limits, conjecture an analogous relation for npoint Amplitudes. The simplicity of the relation is consistent with intuition based on the AdS/CFT correspondence that the form of the large N{sub c} Lloop Amplitudes should be simple enough to allow a resummation to all orders.