Conformal Anomaly for Amplitudes in N=6 Superconformal Chern-Simons   Theory
  Scattering amplitudes in three-dimensional N=6 Chern-Simons theory are shown to be non-invariant with respect to the free representation of the osp(6|4) symmetry generators. At tree and one-loop level these "anomalous" terms occur only for non-generic, singular configurations of the external momenta and can be used to determine the form of the amplitudes. In particular we show that the symmetries predict that the one-loop six-point amplitude is non-vanishing and confirm this by means of an explicit calculation using generalized unitarity methods. We comment on the implications of this finding for any putative Wilson loop/amplitude duality in N=6 Chern-Simons theory. 
Till Bargheer, Niklas Beisert, Florian Loebbert, Tristan McLoughlin
hep-th