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arXiv · 0705.4305

Consistency Conditions on the S-Matrix of Massless Particles

Paolo Benincasa·Freddy Cachazo
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Abstract

We introduce a set of consistency conditions on the S-matrix of theories of massless particles of arbitrary spin in four-dimensional Minkowski space-time. We find that in most cases the constraints, derived from the conditions, can only be satisfied if the S-matrix is trivial. Our conditions apply to theories where four-particle scattering amplitudes can be obtained from three-particle ones via a recent technique called BCFW construction. We call theories in this class constructible. We propose a program for performing a systematic search of constructible theories that can have non-trivial S-matrices. As illustrations, we provide simple proofs of already known facts like the impossibility of spin $s > 2$ non-trivial S-matrices, the impossibility of several spin 2 interacting particles and the uniqueness of a theory with spin 2 and spin 3/2 particles.

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Paolo Benincasa, Freddy Cachazo. 2008-01-17. Consistency Conditions on the S-Matrix of Massless Particles. https://arxiv.org/abs/0705.4305

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