Heavy Flavour Physics: a Probe of Nature’s Grand Design

Book excerpt: The lectures collected in this book present a comprehensive review of the current knowledge of heavy-quark physics, from the points of view of both theory and experiment. Heavy Flavour Physics has accomplished enormous progress during the last few years: the last heavy quark has been discovered and the quality of the collected data on the other relatively lighter quarks has dramatically improved. On the theory side, noticeable progress has been reported on new calculations of decay rates based on various techniques, such as QCD sum rules, heavy-quark mass expansion and lattice QCD. The theory of heavy quark production is constantly improving and awaiting new results. Nevertheless there are strong reasons to believe that the Standard Model of High Energy Physics is incomplete. It exhibits very peculiar patterns for which it offers no explanation. The basic constituents of matter are arranged into three seemingly identical generations or families of quarks and leptons, differing merely in their masses. The pattern in the fermion masses, why they are families and why there are three of them is not yet understood. Furthermore it is known that at least within the standard model there is an intimate connection between the replication of families and the gateway of CP violation, in addition, the latter phenomenon is a crucial ingredient in explaining why our universe is made up almost exclusively of matter rather than being more or less matter-antimatter symmetric. How and to what extent can Heavy Flavour Physics impact on these questions? Does it offer novel windows onto New Physics beyond the Standard Model in general and onto new symmetries, such as Supersymmetry in particular? These questions constitute the central theme of this book. The material treated in this publication may serve as reference for the segment of the high-energy community actively engaged in heavy-quark physics.