Study of |Vtd/Vts| Using a Sum of Exclusive B->X gamma Final States Reconstructed with the BaBar Detector

by Mark Tibbets (Imperial College)

Radiative penguin decays of B mesons are flavour-changing neutral currents (FCNC), studies of which provide precision tests of the Standard Model. Such transitions proceed through 1-loop or higher order processes; they are rare and their amplitudes can potentially be sensitive to interference from FCNC interactions beyond the SM. I will present the results of a study carried out by members of the Imperial HEP group, utilising the complete Y(4S) dataset of the BaBar experiment to analyse the rare inclusive radiative penguin process b->d gamma. I will explain how this study can be used to estimate the ratio of CKM matrix elements |Vtd/Vts|, providing a complementary measurement of these CKM parameters to the existing estimates from B-mixing and exclusive radiative penguin decays.