Measurement of Inclusive Radiative<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>B</mml:mi></mml:math>-Meson Decays with a Photon Energy Threshold of 1.7 GeV

Abstract

Using $605\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of data collected at the $\ensuremath{\Upsilon}(4S)$ resonance we present a measurement of the inclusive radiative $B$-meson decay channel, $B\ensuremath{\rightarrow}{X}_{s}\ensuremath{\gamma}$. For the lower photon energy thresholds of 1.7, 1.8, 1.9, and 2.0 GeV, as defined in the rest frame of the $B$ meson, we measure the partial branching fraction and the mean and variance of the photon energy spectrum. At the 1.7 GeV threshold we obtain the partial branching fraction $\mathrm{BF}(B\ensuremath{\rightarrow}{X}_{s}\ensuremath{\gamma})=(3.45\ifmmode\pm\else\textpm\fi{}0.15\ifmmode\pm\else\textpm\fi{}0.40)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$, where the errors are statistical and systematic.