title: Direct proof of the tree-level scattering amplitude recursion relation in Yang-mills theory.
abstract: Recently, by using the known structure of one-loop scattering amplitudes for gluons in Yang-Mills theory, a recursion relation for tree-level scattering amplitudes has been deduced. Here, we give a short and direct proof of this recursion relation based on properties of tree-level amplitudes only.
authors.affiliation: School of Natural Sciences, Institute for Advanced Study, Princeton, NJ 08540, USA.
authors.forename: Ruth
authors.initials: R
authors.lastname: Britto
authors.forename: Freddy
authors.initials: F
authors.lastname: Cachazo
authors.forename: Bo
authors.initials: B
authors.lastname: Feng
authors.forename: Edward
authors.initials: E
authors.lastname: Witten