Precision measurement of the B → Xs γ photon energy spectrum, branching fraction, and direct CP asymmetry A(CP)((B → X(s+d)γ)

• Published in: Physical review letters Vol. 109; no. 19; p. 191801
• Main Authors: Lees, J P, Poireau, V, Tisserand, V, Garra Tico, J, Grauges, E, Palano, A, Eigen, G, Stugu, B, Brown, D N, Kerth, L T, Kolomensky, Yu G, Lynch, G, Koch, H, Schroeder, T, Asgeirsson, D J, Hearty, C, Mattison, T S, McKenna, J A, So, R Y, Khan, A, Blinov, V E, Buzykaev, A R, Druzhinin, V P, Golubev, V B, Kravchenko, E A, Onuchin, A P, Serednyakov, S I, Skovpen, Yu I, Solodov, E P, Todyshev, K Yu, Yushkov, A N, Bondioli, M, Kirkby, D, Lankford, A J, Mandelkern, M, Atmacan, H, Gary, J W, Liu, F, Long, O, Vitug, G M, Campagnari, C, Hong, T M, Kovalskyi, D, Richman, J D, West, C A, Eisner, A M, Kroseberg, J, Lockman, W S, Martinez, A J, Schumm, B A, Seiden, A, Winstrom, L, Chao, D S, Cheng, C H, Echenard, B, Flood, K T, Hitlin, D G, Ongmongkolkul, P, Porter, F C, Rakitin, A Y, Andreassen, R, Huard, Z, Meadows, B T, Sokoloff, M D, Sun, L, Bloom, P C, Ford, W T, Gaz, A, Nauenberg, U, Smith, J G, Wagner, S R, Ayad, R, Toki, W H, Spaan, B, Schubert, K R, Schwierz, R, Bernard, D, Verderi, M, Clark, P J, Playfer, S, Bettoni, D, Bozzi, C, Calabrese, R, Cibinetto, G, Fioravanti, E, Garzia, I, Luppi, E, Munerato, M, Piemontese, L, Santoro, V, Baldini-Ferroli, R, Calcaterra, A, de Sangro, R, Finocchiaro, G, Patteri, P, Peruzzi, I M, Piccolo, M, Rama, M, Zallo, A, Contri, R
• Format: Journal Article
• Language: English
• Published: United States 09.11.2012
• Subjects: Mesons; Models, Theoretical; Nuclear Energy; Nuclear Physics - methods; Photons
• ISSN: 1079-7114

The photon spectrum in the inclusive electromagnetic radiative decays of the B meson, B → X(s)γ plus B → X(d)γ, is studied using a data sample of (382.8 ± 4.2) × 10(6)Υ(4S) → BB decays collected by the BABAR experiment at SLAC. The spectrum is used to extract the branching fraction B(B → X(s)γ) = (3.21 ± 0.33) × 10(-4) for E(γ) >1.8 GeV and the direct CP asymmetry A(CP) (B → X(s+d)γ) = 0.057 ± 0.063. The effects of detector resolution and Doppler smearing are unfolded to measure the photon energy spectrum in the B meson rest frame.