CP Violation and Beauty Decays -- A Case Study of High Impact, High Sensitivity and Even High Precision Physics

Abstract

The narrative of these lectures contains three main threads: (i) CP violation despite having so far been observed only in the decays of neutral kaons has been recognized as a phenomenon of truly fundamental importance. The KM ansatz constitutes the minimal implementation of CP violation: without requiring unknown degrees of freedom it can reproduce the known CP phenomenology in a nontrivial way. (ii) The physics of beauty hadrons -- in particular their weak decays -- opens a novel window onto fundamental dynamics: they usher in a new quark family (presumably the last one); they allow us to determine fundamental quantities of the Standard Model like the $b$ quark mass and the CKM parameters $V(cb)$, $V(ub)$, $V(ts)$ and $V(td)$; they exhibit speedy or even rapid $B^0 - \bar B^0$J oscillations. (iii) Heavy Quark Expansions allow us to treat $B$ decays with an accuracy that would not have been thought possible a mere decade ago. These three threads are joined together in the following manner: (a) Huge CP asymmetries are {\em pre}dicted in $B$ decays, which represents a decisive test of the KM paradigm for CP violation. (b) Some of these predictions are made with high {\em parametric} reliability, which (c) can be translated into {\em numerical} precision through the judicious employment of novel theoretical technologies. (d) Beauty decays thus provide us with a rich and promising field to search for New Physics and even study some of its salient features. At the end of it there might quite possibly be a New Paradigm for High Energy Physics. There will be some other threads woven into this tapistry: electric dipole moments, and CP violation in other strange and in charm decays.

LATEX, 76 pages, no figures; lectures given at the First APCTP Hadron Physics Winter School, Feb. 23 - 27, 1998, APCTP, Seoul, Korea; three references, in particular one to a recent paper by Pirjol and Uraltsev on four-fermion operators have been added