A DETERMINATION OF THE CKM ANGLE-ALPHA USING MIXING-INDUCED CP VIOLATION IN THE DECAYS B-D-]PI(-) AND B-D-]K-0(K)OVER-BAR(0)()PI()

We present a method of determining the CKM angle a by performing simul taneous measurements of the mixing-induced CP asymmetries of the decay s B-d --> pi(+)pi(-) and B-d --> K-0 (K) over bar(0). The accuracy of our approach is limited by SU(3)-breaking effects originating from (b) over bar --> (d) over bar s (s) over bar QCD-penguin diagrams. Using plausible power-counting arguments we show that these uncertainties ar e expected to be of the same order as those arising through electrowea k penguins in the standard Gronau-London method in which a is extracte d by means of isospin relations among B --> pi pi decay amplitudes, Th erefore our approach, which does not involve the experimentally diffic ult mode B-d --> pi(0) pi(0) and is essentially unaffected by electrow eak penguins, may be an interesting alternative to determine alpha.