2016/12/31 by Laurentiu Rodina
Physics and Astronomy · #hep-th
paper · pdf · doi:10.1007/jhep09(2019)078
published as JHEP09(2019)078 · 13 pages; v2 typo fixed in eq. (2.1); v3: minor revision
arxiv created 2019/08/05 · arxiv updated 2019/09/17
We introduce a BCFW shift which can be used to recursively build the full Yang-Mills tree-level amplitude as a function of polarization vectors. Furthermore, in line with the recent results of arXiv:1612.02797, we conjecture that the Yang-Mills tree-level scattering amplitude is uniquely fixed by locality and demanding the usual asymptotic behavior under a sufficient number of shifts. Unitarity therefore emerges from locality and constructability. We prove this statement at the leading order in the soft expansion.