  Long-range Rydberg interactions, in combination with electromagnetically
induced transparency (EIT), give rise to strongly interacting photons where the
strength, sign, and form of the interactions are widely tunable and
controllable. Such control can be applied to both coherent and dissipative
interactions, which provides the potential to generate novel few-photon states.
Recently it has been shown that Rydberg-EIT is a rare system in which
three-body interactions can be as strong or stronger than two-body
interactions. In this work, we study a three-body scattering loss for
Rydberg-EIT in a wide regime of single and two-photon detunings. Our numerical
simulations of the full three-body wavefunction and analytical estimates based
on Fermi's Golden Rule strongly suggest that the observed features in the
outgoing photonic correlations are caused by the resonant enhancement of the
three-body losses.
