MHV-SQCD的正则变换和CSW的重顶点

超对称规范理论中的单圈MHV振幅

One-Loop MHV Amplitudes in Supersymmetric Gauge Theories

利用由MHV顶点构造标量Feynman图的CSW规则，计算了$\mathcal {N}=1$手征多重态对单圈MHV胶子振幅的贡献。结果与以前使用基于么正性的方法得到的结果一致，从而证明了MHV图技术的有效性，在单圈MHV振幅的情况下，对所有无质量超对称理论。

Holonomies of gauge fields in twistor space 4: functional MHV rules and one-loop amplitudes

We consider generalization of the Cachazo-Svrcek-Witten (CSW) rules to one-loop amplitudes of N=4 super Yang-Mills theory in a recently developed holonomy formalism in twistor space. We first reconsider off-shell continuation of the Lorentz-invariant Nair measure for the incorporation of loop integrals. We then formulate an S-matrix functional for general amplitudes such that it implements the CSW rules at quantum level. For one-loop MHV amplitudes, the S-matrix functional correctly reproduces the analytic expressions obtained in the Brandhuber-Spence-Travaglini (BST) method. Motivated by this…

费米MHV顶点的六夸克振幅

Six-Quark Amplitudes from Fermionic MHV Vertices

将CSW方法推广到与费米子耦合的微扰规范理论，计算了六夸克QCD振幅。我们发现使用通常的费曼规则所获得的结果完全一致。

The MHV lagrangian vertices and the Parke-Taylor formula

We explicitly calculate the vertices of the MHV-rules lagrangian in 4-dimensions. This proves that the vertices in the lagrangian obtained by a canonical transformation from light-cone Yang-Mills theory coincide to all order with the Parke-Taylor formula, filling the gap originally left in the lagrangian derivation of the CSW rules.

重力振幅的MHV-顶点

MHV-Vertices for Gravity Amplitudes

我们得到了计算引力子散射振幅的CSW形式，并通过使用一种特殊类型的BCFW类参数位移证明了它的有效性。该程序说明了明确的例子。

MHV规则拉格朗日量的结构

Structure of the MHV-rules Lagrangian

最近，提出了场变量的正则变换，将杨-米尔斯拉格朗日变换为MHV规则拉格朗日，即其树级费曼图展开生成CSW规则的拉格朗日。我们解决的关系定义的典型的变换，在新领域的所有订单的扩展，产生简单的显式全纯表达式的扩展系数。我们使用这些来明确地确认三个、四个和五个点顶点与具有正确系数的MHV振幅成比例，正如预期的那样。我们指出了这个框架的几个后果，并开始在量子水平上的MHV规则的影响的研究。特别是，我们调查的波函数匹配因子隐含的等价定理在一个循环，并表明，他们可能会消失在维正则化。

S-矩阵等价定理的规避和规范MHV拉格朗日量的维度正则化

S-Matrix Equivalence Theorem Evasion and Dimensional Regularisation with the Canonical MHV Lagrangian

我们证明，正则变量的变化，产生的MHV拉格朗日，也提供了贡献的散射振幅，逃避等价定理。这种“ET规避”特别提供了树级（-++）振幅，其在壳外或在壳上具有复杂动量或在（2，2）签名，并且在MHV（aka CSW）规则中缺失。在一个环有ET回避图解贡献的振幅与所有正螺旋度。我们提供必要的正则化，以定义这些贡献（和量子MHV方法一般）从光锥杨-米尔斯拉格朗日在D维和正则变化的变量的所有D-2横向自由度的规范场。通过这种方式，我们获得了三维正则化的三点和四点MHV振幅。回到单圈（+）振幅，我们证明了它的四重切割与已知的结果相一致，并显示了原来的光锥杨米尔斯贡献实际上可以从ET-回避的贡献代数恢复。我们的结论是，正则MHV拉格朗日量，加上非线性场变换给关联函数带来的额外项，所提供的贡献只是轻锥Yang-Mills贡献的重新排列，因此在壳层内外都与它们一致。

A new Wilson Line-based classical action for gluodynamics

We develop a new classical action that in addition to $\mathrm{MHV}$ vertices contains also $\mathrm{N^kMHV}$ vertices, where $1\leq k \leq n-4$ with $n$ the number of external legs. The lowest order vertex is the four-point MHV vertex -- there is no three point vertex and thus the amplitude calculation involves fewer vertices than in the CSW method and, obviously, considerably fewer than in the standard Yang-Mills action. The action is obtained by a canonical transformation of the Yang-Mills action in the light-cone gauge, where the field transformations are based on the Wilson line functiona…

Local Spacetime Physics from the Grassmannian

A duality has recently been conjectured between all leading singularities of n-particle N^(k-2)MHV scattering amplitudes in N=4 SYM and the residues of a contour integral with a natural measure over the Grassmannian G(k,n). In this note we show that a simple contour deformation converts the sum of Grassmannian residues associated with the BCFW expansion of NMHV tree amplitudes to the CSW expansion of the same amplitude. We propose that for general k the same deformation yields the (k-2) parameter Risager expansion. We establish this equivalence for all MHV-bar amplitudes and show that the Risa…

A new Wilson line-based action for gluodynamics

We perform a canonical transformation of fields that brings the Yang-Mills action in the light-cone gauge to a new classical action, which does not involve any triple-gluon vertices. The lowest order vertex is the four-point MHV vertex. Higher point vertices include the MHV and $\overline{\textrm{MHV}}$ vertices, that reduce to the corresponding amplitudes in the on-shell limit. In general, any $n$-leg vertex has $2\leq m \leq n-2$ negative helicity legs. The canonical transformation of fields can be compactly expressed in terms of path-ordered exponentials of fields and their functional deriv…

MHV QCD拉格朗日量

The MHV QCD Lagrangian

我们进行光锥规范无质量QCD的场变量的正则变化，以获得一个拉格朗日项的偏振因子成比例的MHV振幅和继续由CSW处方壳外。我们解决了这个变换作为一个系列的扩展到所有的订单在新的领域，并使用它来证明所得到的顶点确实是MHV顶点声称。我们还演示了这是如何明确的顶点工程：两个夸克和两个胶子，四个夸克，和一个特定的螺旋配置的两个夸克和三个胶子。最后，我们推广到大质量QCD的建设。