Theory of the endpoint region of exclusive rare B decays

Abstract

In the ratio of ratios of rates for radiative and semileptonic decays of B and D to K* and rho mesons the non-computable form factors mostly cancel out. The resulting method for the determination of Vub is largely free of hadronic uncertainties, raising the prospect of a precise determination of Vub.

Comments: 4 pages, 2 figures, talk presented at ICHEP04, Beijing, China, August 2004