Theory Seminar: Ian Moult

Speaker: Ian Moult (SLAC)

Title: Jet Substructure, Lightray Operators and Spinning Gluons

Abstract: The detailed internal structure of jets encodes valuable information about the interactions of high energy quarks and gluons, and their confinement into color-neutral hadrons. Theoretically, the flow of energy within jets is characterized by non-local lightray operators, which measure the distribution of energy at null infinity in collider experiments. In this talk I will first use Open Data to show that matrix elements of multiple lightray operators can be directly measured in collider experiments, leading to a new perspective on jet substructure. I will then show that techniques developed in the study of conformal field theories, in particular the lightray operator product expansion (OPE), provide powerful approaches to understanding the small angle behavior of these observables. Finally, I will highlight an interesting transverse spin effect that arises due to the quantum mechanical interference of intermediate gluons of different helicities, and imprints an azimuthal modulation pattern onto the energy deposited in a detector.