PRECISE DETERMINATIONS OF THE CKM MATRIX FROM CP-ASYMMETRIES IN B-DECAYS AND KL-]PI(0)NU(NU)OVER-BAR

We point out that the measurements of the CP asymmetries in neutral B- decays together with a measurement of Br(4K(L) --> pi0nunuBAR) and the known value of \V(us)\ can determine all elements of the Cabibbo-Koba yashi-Maskawa matrix without essentially any hadronic uncertainties. I n particular the strong dependence of Br(K(L) --> pi0nunuBAR) on \V(cb )\ (\V(cb)\4) can be used to determine this element precisely. Consequ ently \V(ub)\, \V(td)\ and \V(ts)\ can also be determined. We derive a set of formulae which facilitate this study and we present a numerica l analysis of several future scenarios. Accurate determinations of all parameters are expected from the B-factories and the Main Injector er a at Fermilab including KAMI. An impressive accuracy should be reached in the LHC era. An analysis using Br(K+ --> pi+nunuBAR) instead of Br (K(L) --> pi0nunuBAR) shows that although the determination of \V(cb)\ and \V(td)\ this way is less accurate, still useful results for these elements can be obtained.