From chiral to conformal anomalies: a double copy perspective for CFT correlators

Abstract

We uncover a double-copy relation between chiral and conformal anomalies in four-dimensional conformal field theory. We show that this relation extends from local anomaly structures to complete momentum-space three-point correlators and, through their flat-space limits, to five-dimensional scattering amplitudes. In particular, the parity-odd current correlators associated with the chiral anomaly reduce, in the flat-space limit, to a universal amplitude generated by a Chern--Simons interaction. Squaring these anomalous current correlators reproduces the contribution to the stress-tensor three-point function $\langle TTT\rangle$, controlled by the conformal anomaly, thereby establishing a direct link between chiral- and conformal-anomaly structures.