Topic: QCD

Scattering amplitudes constrain effective field theories from the bottom up through general consistency requirements, including unitarity and causality. Existing bounds mainly use four-point amplitudes. This talk explains how amplitudes with more external points supply additional constraints beyond the four-point analysis, and demonstrates the method through an application to Large-Nc quantum chromodynamics.

Benoit Assi examines limits on reliable theoretical predictions for present and future particle colliders. Low-order simulations of QCD radiation carry large uncertainties, hadronization is commonly modeled rather than derived, and effective theories contain more operators than measurements can constrain. Information theory and machine learning can incorporate improved calculations into simulations, quantify uncertainty, choose informative observables and advance hadronization theory. Geometry of effective-theory field space combines infinite operator families into finite physical quantities,