Results from the BaBar Fully Inclusive Measurement of $B\to X_s\gamma$

Abstract

We present preliminary results from a lepton-tagged fully-inclusive measurement of $B\to X_s\gamma$ decays, where $X_s$ is any strange hadronic state. Results are based on a BaBar data set of 88.5 million $B\bar{B}$ pairs at the ${\rm Y}(4S)$ resonance. We present a reconstructed photon energy spectrum in the ${\rm Y}(4S)$ frame, and partial branching fractions above minimum reconstructed photon energies of 1.9, 2.0, 2.1 and 2.2 GeV. We then convert these to measurements of partial branching fractions and truncated first and second moments of the true photon energy distribution in the B rest frame, above the same minimum photon energy values. The full correlation matrices between the first and second moments are included to allow fitting to any parameterized theoretical calculation. We also measure the direct CP asymmetry $A_{cp}(B\to X_{s+d}\gamma )$ (based on the charge of the tagging lepton) above a reconstructed photon energy of 2.2 GeV

arXiv comment22 pages, 3 postscript figues, submitted to Lepton-Photon 2005