Journal of High Energy Physics (Jul 2017)
From 4d ambitwistor strings to on shell diagrams and back
Abstract
Abstract We investigate the relation between 4d ambitwistor string theory and on-shell diagrams for planar N = 4 $$ \mathcal{N}=4 $$ super-Yang-Mills and N = 8 $$ \mathcal{N}=8 $$ supergravity, and deduce several new results about their scattering amplitudes at tree-level and 1-loop. In particular, we derive new Grassmannian integral formulae for tree-level amplitudes and obtain new world-sheet formulae for 1-loop amplitudes which are manifestly supersymmetric and supported on scattering equations refined by MHV degree.
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