This PhD thesis is dedicated to a subfield of elementary particle physics called "Flavour Physics". The Standard Model of Particle Physics (SM) has been confirmed by thousands of experimental measurements with a high precision. But the SM leaves important questions open, like what is the nature of dark matter or what is the origin of the matter-antimatter asymmetry in the Universe. By comparing high precision Standard Model calculations with extremely precise measurements, one can find the first glimpses of the physics beyond the SM - currently we see the first hints of a potential breakdown of the SM in flavour observables. This can then be compared with purely theoretical considerations about new physics models, known as model building. Both precision calculations and model building are extremely specialised fields and this outstanding thesis contributes significantly to both topics within the field of Flavour Physics and sheds new light on the observed anomalies.

Matthew Kirk is a particle physicist, whose main research interest is in Flavour Physics with a particular focus on B meson mixing. He completed an M.Sci in Natural Sciences at King's College, University of Cambridge before going to Grey College, Durham University, where he studied for a PhD at the Institute for Particle Physics Phenomenology under the supervision of Alexander Lenz. He is currently a postdoctoral researcher at La Sapienza, University of Rome.