Detector operators, of which the average null energy operator provides the most famous example, arise as direct theoretical models of asymptotic measurements in collider experiments. In QFT, detector operators are expressed in terms of "light-ray operators", whose correlation functions provide an interesting class of non-perturbatively well-defined observables.

In this talk, I will give an overview of light-ray/ detector operators, and attempt highlight the different perspectives and motivations for studying these operators, coming from the CFT, amplitudes and phenomenological communities. I will then present recent measurements of these correlators in experiment, as well as applications to positivity bounds on OPE coefficients.