Quark mixing, CP violation and rare decays after the top quark discovery

Abstract

We review the highlights of quark mixing, particle-antiparticle mixing, CP violation and rare K- and B-decays in the Standard Model. The top quark discovery, the precise measurement of its mass, the improved knowledge of the couplings $V_{cb}$ and $V_{ub}$, and the calculations of NLO short distance QCD corrections improved considerably the predictions for various decay rates, the determination of the couplings $V_{td}$ and $V_{ts}$ and of the complex phase in the Cabibbo-Kobayashi-Maskawa matrix. After presenting the general theoretical framework for weak decays, we discuss the following topics in detail: i) the CKM matrix, its most convenient parametrizations and the unitarity triangle, ii) the CP-violating parameter $ε_K$ and $B^0_{d,s}-\bar B^0_{d,s}$ mixings, iii) the ratio $ε'/ε$, iv) the rare K-decays $K_L\toπ^0e^+e^-$, $K^+\toπ^+ν\barν$, $K_L\toπ^0ν\barν$ and $K_L\toμ^+μ^-$, v) the radiative decays $B\to X_sγ$ and $B\to X_s l^+l^-$, vi) the rare B-decays $B\to X_{s,d}ν\barν$ and $B_{d,s}\to l^+l^-$, vii) CP violation in neutral and charged B-decays putting emphasis on clean determinations of the angles of the unitarity triangle, and viii) the role of electroweak penguins in B-decays. We present several future visions demonstrating very clearly the great potential of CP asymmetries in B-decays and of clean K-decays such as $K^+\toπ^+ν\barν$ and $K_L\toπ^0ν\barν$ in the determination of the CKM parameters and in decisive testing of the Standard Model. An outlook for the coming years ends our review.

180 pages, 35 figures, LaTeX. To appear in Heavy Flavours II, World Scientific (1997), Eds. A.J. Buras and M. Lindner. The complete paper is also available via anonymous ftp at ftp://www-ttp.physik.uni-karlsruhe.de/ , or via www at http://www-ttp.physik.uni-karlsruhe.de/cgi-bin/preprints/