Yangian symmetry of scattering amplitudes in N=4 super Yang-Mills theory
Yangian symmetry of scattering amplitudes in N=4 super Yang-Mills theory
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DOI：
10.1088/1126-6708/2009/05/046
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发表时间：
2009-02
影响因子：
5.4
通讯作者：
J. Drummond;J. Henn;J. Plefka
中科院分区：
文献类型：
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作者：
J. Drummond;J. Henn;J. Plefka
= 4 super Yang-Mills 理论中的树级散射振幅最近被证明可以相对于“对偶”超共形对称代数进行协变变换，从而扩展了该理论的传统超共形对称代数 psu(2,2|4)。在本文中，我们推导了壳超空间中双超共形发生器的作用，并适当扩展了双发生器以使散射幅度保持不变。然后，我们研究了标准和对偶对称生成元的代数，并表明包含对偶超共形生成元将 psu(2,2|4) 对称代数提升为 Yangian。由于 psu(2,2|4) 的特殊性质，作用于振幅的非局部杨格生成元被证明是循环不变的。 Yangian 生成器的表示形式与局部算子的情况相同，这表明 Yangian 对称性是 planar = 4 super Yang-Mills 的固有属性，至少在树级别如此。
Tree-level scattering amplitudes in = 4 super Yang-Mills theory have recently been shown to transform covariantly with respect to a `dual' superconformal symmetry algebra, thus extending the conventional superconformal symmetry algebra psu(2,2|4) of the theory. In this paper we derive the action of the dual superconformal generators in on-shell 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(2,2|4) symmetry algebra to a Yangian. The non-local Yangian generators acting on amplitudes turn out to be cyclically invariant due to special properties of psu(2,2|4). The representation of the Yangian generators takes the same form as in the case of local operators, suggesting that the Yangian symmetry is an intrinsic property of planar = 4 super Yang-Mills, at least at tree level.