CKM Parameters and Rare B Decays

Abstract

Measurements of the angles and sides of the unitarity triangle and of the rates of rare B meson decays are crucial for the precise determination of Standard Model parameters and are sensitive to the presence of new physics particles in the loop diagrams. In this paper the recent measurements performed in this area by Babar and Belle will be presented. The direct measurement of the angle alpha is for the first time as precise as the indirect determination. The precision of the V_ub determination has improved significantly with respect to previous measurement. New limits on B->tau nu decays are presented, as well as updated measurements on b->s radiative transitions and a new observation of b->d gamma transition made by Belle.