Note on Cyclic Sum and Combination Sum of Color-ordered Gluon Amplitudes
Abstract
Continuing our previous study \cite{Du:2011se} of permutation sum of color ordered tree amplitudes of gluons, in this note, we prove the large- behavior of their cyclic sum and the combination of cyclic and permutation sums under BCFW deformation. Unlike the permutation sum, the study of cyclic sum and the combination of cyclic and permutation sums is much more difficult. By using the generalized Bern-Carrasco-Johansson (BCJ) relation, we have proved the boundary behavior of cyclic sum with nonadjacent BCFW deformation. The proof of cyclic sum with adjacent BCFW deformation is a little bit simpler, where only Kleiss-Kuijf (KK) relations are needed. Finally we have presented a new observation for partial-ordered permutation sum and applied it to prove the boundary behavior of combination sum with cyclic and permutation.
Keywords
Cite
@article{arxiv.1111.5691,
title = {Note on Cyclic Sum and Combination Sum of Color-ordered Gluon Amplitudes},
author = {Yi-Jian Du and Bo Feng and Chih-Hao Fu},
journal= {arXiv preprint arXiv:1111.5691},
year = {2015}
}
Comments
21 pages, improved version