Feynman Rules of Higher-order Poles in CHY Construction
arXiv:1604.07314 · doi:10.1007/JHEP06(2016)013
Abstract
In this paper, we generalize the integration rules for scattering equations to situations where higher-order poles are present. We describe the strategy to deduce the Feynman rules of higher-order poles from known analytic results of simple CHY-integrands, and propose the Feynman rules for single double pole and triple pole as well as duplex-double pole and triplex-double pole structures. We demonstrate the validation and strength of these rules by ample non-trivial examples.
52 pages, 37 figures