Inclusive Measurement of the Photon Energy Spectrum in b→sγ Decays

We report a fully inclusive measurement of the flavor changing neutral current decay b-->sgamma in the energy range 1.8 GeVless than or equal toE(gamma)(*)less than or equal to2.8 GeV, covering 95% of the total spectrum. Using 140 fb(-1), we obtain B(b-->sgamma)=(3.55+/-0.32(-0.31-0.07)(+0.30+0.11))x10(-4), where the errors are statistical, systematic, and from theory corrections. We also measure the first and second moments of the photon energy spectrum above 1.8 GeV and obtain =2.292+/-0.026+/-0.034 GeV and - (2)=0.0305+/-0.0074+/-0.0063 GeV2, where the errors are statistical and systematic.