| Thème(s) : |
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Physique/Physique des Hautes Energies - Expérience
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| Titre : |
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Precision Measurement of the B to X_s \gamma Photon Energy Spectrum, Branching Fraction, and Direct CP Asymmetry A_{CP}(B to X_{s+d}\gamma |
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| Auteur : |
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J. P. Lees1, V. Poireau1, V. Tisserand1, D. Bernard2, M. Verderi2, S. Emery3, G. Hamel de Monchenault3, G. Vasseur3, Ch. Yèche3, N. Arnaud4, M. Davier4, D. Derkach4, G. Grosdidier4, F. Le Diberder4, A. M. Lutz4, B. Malaescu4, P. Roudeau4, M. H. Schune4, A. Stocchi4, G. Wormser4, S. Akar5, E. Ben-Haim5, M. Bomben5, G.R. Bonneaud5, H. Briand5, G. Calderini5, J. Chauvau5, O. Hamon5, Ph. Leruste5, G. Marchiori5, J. Ocariz5, S. Sitt5 |
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| Laboratoire : |
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| Résumé : |
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The photon spectrum in the inclusive electromagnetic radiative decays of the $B$ meson, $B \to X_{s} \gamma$ plus $B \to X_{d} \gamma$, is studied using a data sample of $(382.8 \pm 4.2) \times 10^6$ $\Upsilon(4S) \to B\overli\ ne{B}$ decays collected by the \babar\ experiment at SLAC. The spectrum is used to extract the branching fraction ${\cal B}(B \to X_{s} \gamma)=(3.21 \pm 0.33)\times 10^{-4}$ for $E_{\gamma}>1.8 \gev$ and the direct CP asymmetry $A_{CP}(B \to X_{s+d} \gamma)=0.057 \pm 0.063$. The effects of detector resolution and Doppler smearing are unfolded to measure the photon energy spectrum in the $B$ meson rest frame. |
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| Collaboration/Projet : |
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BABAR |
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| Type de publication : |
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Articles dans des revues avec comité de lecture |
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Date de publication ou d'écriture : |
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2012 |
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| Nom du périodique : |
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| Physical Review Letters (Phys. Rev. Lett.) |
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American Physical Society |
| ISSN |
0031-9007 (eISSN : 1079-7114) |
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| Volume : |
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109 |
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| Page/Article : |
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191801 |
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| Identifiant local : |
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SLAC-PUB-15180 |
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| Commentaire : |
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8 pages, 2 figures, submitted to PRL - See paper for full list of authors |
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