Thesis defense of Dennis Loose

Current experimental data on the flavor observables RK and RK shows evidence for a violation of lepton universality – an essential feature of the Standard Model of particle physics. Together with several deviations seen in other b ! sμ+μ− observables as well as RD and RD*, these results constitute the so-called B decay anomalies. In this thesis we investigate new physics models that provide potential solutions to these anomalies and put a special emphasis on their flavor structure. To this end, we consider an A4×UFN(1)-based flavor symmetry, which addresses the SM flavor puzzle, and study patterns that it imposes on the couplings of leptoquark models. We find that flavorful leptoquarks provide good explanations of RK() , while constraints from rare kaon decays and charged lepton flavor violating processes are too strong to allow to accommodate the deviations in RD(*). As another consequence of the imposed flavor structure, flavorful leptoquarks are light enough to be produced at current and future hadron colliders. We compute estimates for the production cross sections of the S3, V1 and V3 leptoquarks in different flavor scenarios, focusing on single production, which is sensitive to the leptoquark coupling and its flavor structure. We find that future hadron colliders with higher center of mass energies are needed to cover the full parameter space and determine leptoquark mass bound for benchmark scenarios.