Measurement of B (B → X_sγ), the B → X_sγ photon energy spectrum, and the direct CP asymmetry in B → X_(s+d)γ decays
Abstract
The photon spectrum in B → X_sγ decay, where X_s is any strange hadronic state, is studied using a data sample of (382.8±4.2) × 10^6 e^+e^- → Υ(4S) → BB events collected by the BABAR experiment at the PEP-II collider. The spectrum is used to measure the branching fraction B(B → X_sγ)=(3.21±0.15±0.29±0.08) × 10^(-4) and the first, second, and third moments ⟨E_γ⟩=2.267±0.019±0.032±0.003 GeV, ⟨(E_γ-⟨E_γ⟩)^2⟩=0.0484±0.0053±0.0077±0.0005 GeV^2, and ⟨(E_γ-⟨E_γ⟩)^3⟩=-0.0048±0.0011±0.0011±0.0004 GeV^3, for the range E_γ > 1.8 GeV, where E_γ is the photon energy in the B-meson rest frame. Results are also presented for narrower E_γ ranges. In addition, the direct CP asymmetry A_(CP)(B → X_(s+d)γ) is measured to be 0.057±0.063. The spectrum itself is also unfolded to the B-meson rest frame; that is the frame in which theoretical predictions for its shape are made.
Additional Information
© 2012 American Physical Society. Received 25 July 2012; published 28 December 2012. We are grateful for the extraordinary contributions of our PEP-II colleagues in achieving the excellent luminosity and machine conditions that have made this work possible. The success of this project also relies critically on the expertise and dedication of the computing organizations that support BABAR. The collaborating institutions wish to thank SLAC for its support and the kind hospitality extended to them. This work is supported by the U.S. Department of Energy and National Science Foundation, the Natural Sciences and Engineering Research Council (Canada), the Commissariat à l'Energie Atomique and Institut National de Physique Nucléaire et de Physique des Particules (France), the Bundesministerium für Bildung und Forschung and Deutsche Forschungsgemeinschaft (Germany), the Istituto Nazionale di Fisica Nucleare (Italy), the Foundation for Fundamental Research on Matter (The Netherlands), the Research Council of Norway, the Ministry of Education and Science of the Russian Federation, Ministerio de Ciencia e Innovaciόn (Spain), and the Science and Technology Facilities Council (United Kingdom). Individuals have received support from the Marie Curie IEF program (European Union) and the A. P. Sloan Foundation (USA).Attached Files
Published - PhysRevD.86.112008.pdf
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Additional details
- Eprint ID
- 36553
- Resolver ID
- CaltechAUTHORS:20130124-083005947
- Department of Energy (DOE)
- NSF
- Natural Sciences and Engineering Research Council of Canada (NSERC)
- Commissariat à l'Energie Atomique (CEA)
- Bundesministerium für Bildung und Forschung (BMBF)
- Istituto Nazionale di Fisica Nucleare (INFN)
- Stichting voor Fundamenteel Onderzoek der Materie (FOM)
- Research Council of Norway
- Ministry of Education and Science of the Russian Federation
- Ministerio de Ciencia e Innovaciόn (MICINN)
- Science and Technology Facilities Council (STFC)
- Marie Curie Fellowship
- Alfred P. Sloan Foundation
- Institut National de Physique Nucléaire et de Physique des Particules (IN2P3)
- Deutsche Forschungsgemeinschaft (DFG)
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2013-01-24Created from EPrint's datestamp field
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2021-11-09Created from EPrint's last_modified field