Search for the decay (B)over-bar(0) -> D*(0)gamma

Abstract

We report results of a search for the rare radiative decay (B) over bar(0) --> D*(0)gamma. Using 9.66 x 10(6) <B(B)over bar> meson pairs collected with the CLEO detector at the Cornell Electron Storage Ring, we set an upper limit on the branching ratio for this decay of 5.0 x 10(-5) at 90% C.L. This provides evidence that the anomalous enhancement is absent in W-exchange processes and that weak radiative B decays are dominated by the short-distance b --> s gamma mechanism in the standard model.