2014/09/30 by Freddy Cachazo, Song He, Ellis Ye Yuan · 2 citations
Physics and Astronomy · #hep-th
paper · pdf · doi:10.1007/jhep01(2015)121
18 pages. References and a new section on double-trace gluon amplitudes added in v2
arxiv created 2014/10/19 · arxiv updated 2015/06/23
We present the building blocks that can be combined to produce tree-level S-matrix elements of a variety of theories with various spins mixed in arbitrary dimensions. The new formulas for the scattering of n massless particles are given by integrals over the positions of n points on a sphere restricted to satisfy the scattering equations. As applications, we obtain all single-trace amplitudes in Einstein--Yang--Mills (EYM) theory, and generalizations to include scalars. Also in EYM but extended by a B-field and a dilaton, we present all double-trace gluon amplitudes. The building blocks are made of Pfaffians and Parke--Taylor-like factors of subsets of particle labels.