Abstract
Using a sample of 471 x 10(6) B (B) over bar events collected with the BABAR detector, we study the sum of seven exclusive final states B -> X-s(d)gamma, where X-s(d) is a strange (nonstrange) hadronic system with a mass of up to 2.0 GeV/c(2). After correcting for unobserved decay modes, we obtain a branching fraction for b -> d gamma of (9.2 +/- 2.0(stat) +/- 2.3(syst) x 10(-6) in this mass range, and a branching fraction for b -> s gamma of (23.0 +/- 0.8(stat) +/- 3.0(syst) x 3.0(syst) x 10(-5) in the same mass range. We find B(b -> d gamma)/B(b -> s gamma) = 0.040 +/- 0.009(stat) +/- 0.010(syst), from which we determine vertical bar Vtd/Vts vertical bar = 0.199 +/- 0.022(stat) +/- 0.024(syst) +/- 0.002(th).
We are grateful for the excellent luminosity and machine
conditions provided by our PEP-II colleagues, and
for the substantial dedicated effort from the computing
organizations that support BABAR. The collaborating
institutions wish to thank SLAC for its support and
kind hospitality. This work is supported by DOE and
NSF (USA), NSERC (Canada), CEA and CNRS-IN2P3
(France), BMBF and DFG (Germany), INFN (Italy),
FOM (The Netherlands), NFR (Norway), MES (Russia),
MICIIN (Spain), STFC (United Kingdom). Individuals
have received support from the Marie Curie EIF (European
Union), the A. P. Sloan Foundation (USA) and the
Binational Science Foundation (USA-Israel).
Peer reviewed