Observation of the decay B⊃-→Ds(*)+K⊃-⊃- ν̄

Author(s): Del Amo Sanchez, P; Lees, JP; Poireau, V; Prencipe, E; Tisserand, V; GarraTico, J; Grauges, E; Martinelli, M; Palano, A; Pappagallo, M; Eigen, G; Stugu, B; Sun, L; Battaglia, M; Brown, DN; Hooberman, B; Kerth, LT; Kolomensky, YG; Lynch, G; Osipenkov, IL; Tanabe, T; Hawkes, CM; Watson, AT; Koch, H; Schroeder, T; Asgeirsson, DJ; Hearty, C; Mattison, TS; McKenna, JA; Khan, A; Randle-Conde, A; Blinov, VE; Buzykaev, AR; Druzhinin, VP; Golubev, VB; Onuchin, AP; Serednyakov, SI; Skovpen, YI; Solodov, EP; Todyshev, KY; Yushkov, AN; Bondioli, M; Curry, S; Kirkby, D; Lankford, AJ; Mandelkern, M; Martin, EC; Stoker, DP; Atmacan, H; Gary, JW; Liu, F; Long, O; Vitug, GM; Campagnari, C; Hong, TM; Kovalskyi, D; Richman, JD; Eisner, AM; Heusch, CA; Kroseberg, J; Lockman, WS; Martinez, AJ; Schalk, T; Schumm, BA; Seiden, A; Winstrom, LO; Cheng, CH; Doll, DA; Echenard, B; Hitlin, DG; Ongmongkolkul, P; Porter, FC; Rakitin, AY; Andreassen, R; Dubrovin, MS; Mancinelli, G; Meadows, BT; Sokoloff, MD; Bloom, PC; Ford, WT; Gaz, A; Nagel, M; Nauenberg, U; Smith, JG; Wagner, SR | Abstract: We report the observation of the decay B⊃-→Ds(*)+K⊃- ⊃-νbased on 342fb⊃-1 of data collected at the e(4S) resonance with the BABAR detector at the PEP-II e⊃+e⊃- storage rings at SLAC. A simultaneous fit to three Ds+ decay chainsis performed to extract the signal yield from measurements of the squared missing mass in the B mesondecay. We observe the decay B⊃-→Ds(*)+K⊃-⊃- νwith a significance greater than 5 standard deviations (including systematic uncertainties) and measure its branching fractionto be B(B⊃-→Ds(*)+K⊃-⊃-ν)=[6.13-1.03+1. 04(stat)±0.43(syst)±0.51(B(Ds))]×10⊃-4, where the last error reflects the limited knowledge of the Dsbranching fractions. © 2011 American Physical Society.