The CKM matrix: status and some outlook

The status of the CKM matrix is reviewed in the light of the most recent results. Selected topics with respect to future developments are discussed. In 2002, the KM mechanism of CP-violation passed a highly non-trivial test: the measured sin 2β value has been found to be in agreement with the tight constraints on the Wolfenstein parameters ρ and η set by the measurements of |Vub/Vcb|, Δmd and Δms and εK. The B-factories will continue to increase the precision on sin 2β. First measurements of time-dependent CP-asymmetries in B0/B-bar0 → π+π- and B0/B-bar0 → ρ±π-+ have been performed with the goal to constrain the unitarity triangle α. In addition, there are prospects to reduce the theoretical uncertainty on |Vcb| and |Vub| on data. New results on the CKM parameters |Vud| and |Vus| have been published, which are relevant for the extraction of the Wolfenstein parameter λ and to test unitarity in the first quark family. In many cases, the extraction of CKM parameters from data is hampered by theoretical uncertainties which are difficult to treat statistically. Here, we make use of the R-fit approach, in which theoretical parameters are let free to vary in allowed ranges. For a given set of theoretical parameters with corresponding uncertainties, this approach allows to test quantitatively the consistency between data and the Standard Model and to determine Confidence Level's (CL's). For the discussion of other statistical approaches and numerical comparisons between them we refer to paper 'The CKM matrix and the unitarity triangle' by M. Battaglia et al. The paper presents the unitarity violation in the first family, the inputs for a global CKM fit and the results. In addition selected topics beyond the standard CKM fit, namely time-dependent CP-asymmetry in B0 → φKs, rare kaon decays and constraints on α are discussed