# A Scattering Amplitude in Conformal Field Theory

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Marc Gillioz, Marco Meineri, Joao Penedones

Marc Gillioz, Marco Meineri, Joao Penedones

**16/3/20**Published in : arXiv:2003.07361

We define form factors and scattering amplitudes in Conformal Field Theory as the coefficient of the singularity of the Fourier transform of time-ordered correlation functions, as p^2 \to 0. In particular, we study a form factor F(s,t,u) obtained from a four-point function of identical scalar primary operators. We show that F is crossing symmetric, analytic and it has a partial wave expansion. We illustrate our findings in the 3d Ising model, perturbative fixed points and holographic CFTs.