Six-dimensional correlators from a five-dimensional operator product expansion

In this letter we discuss the operator product expansion of scalar operators in five-dimensional field theories with an SU(1, 3) × U(1) spacetime symmetry. Such theories arise by a novel conformal null reduction of six-dimensional Lorentzian conformal field theories. Unlike Lorentzian conformal field theories, three-point functions of generic operators in such theories are not completely fixed by SU(1, 3) × U(1) symmetry. However, we show that in a special case the functional form of the OPE coefficients can be fully determined, and we use them to fix the form of the three-point function. The result is shown to agree with correlation functions obtained by reduction of six-dimensional conformal field theories.