298 articles – 2328 Notices  [english version]
 HAL : in2p3-00193271, version 1
 arXiv : 0711.4889
 Physical Review D 77 (2008) 051103
 Measurement of the $B \to X_{s}\gamma$ Branching Fraction and Photon Energy Spectrum using the Recoil Method
 BABAR Collaboration(s)
 (2008)
 We present a measurement of the branching fraction and photon energy spectrum for the decay B --> X_s gamma using data from the BaBar experiment. The data sample corresponds to an integrated luminosity of 210 fb^{-1}, from which approximately 680 000 BB events are tagged by a fully reconstructed hadronic decay of one of the B mesons. In the decay of the second B meson, an isolated high--energy photon is identified. We measure BR(B --> X_s gamma) = (3.66 +- 0.85_{stat} +- 0.60_{syst}) x 10^{-4} for photon energies E_gamma above 1.9 GeV in the B rest frame. From the measured spectrum we calculate the first and second moments for different minimum photon energies, which are used to extract the heavy-quark parameters m_b and mu_{pi}^2. In addition, measurements of the direct CP asymmetry and isospin asymmetry are presented.
 Thème(s) : Physique/Physique des Hautes Energies - Expérience
 Lien vers le texte intégral : http://fr.arXiv.org/abs/0711.4889
 in2p3-00193271, version 1 http://hal.in2p3.fr/in2p3-00193271 oai:hal.in2p3.fr:in2p3-00193271 Contributeur : Dominique Girod <> Soumis le : Lundi 3 Décembre 2007, 10:32:07 Dernière modification le : Vendredi 11 Avril 2008, 16:32:36