Measurement of $B \to X \gamma$ Decays and Determination of $|V_{td}/V_{ts}|$

Abstract

Using a sample of 383x10(6) BB events collected by the BABAR experiment, we measure sums of seven exclusive final states B -> X-d(s)gamma, where X-d(X-s) is a nonstrange (strange) charmless hadronic system in the mass range 0.6-1.8 GeV/c(2). After correcting for unmeasured decay modes in this mass range, we obtain a branching fraction for b -> d gamma of (7.2 +/- 2.7(stat)+/- 2.3(syst))x10(-6). Taking the ratio of X-d to X-s we find Gamma(b -> d gamma)/Gamma(b -> s gamma)=0.033 +/- 0.013(stat)+/- 0.009(syst), from which we determine |V-td/V-ts|=0.177 +/- 0.043.