Branching Fraction Measurements of the Decays B → η

In this report, we present the observation of the exclusive decays B → ηcK and B → ηcK, and the measurement of the related branching fractions. Using a sample of 22.7×10 Υ (4S) → BB decays collected with the BABAR detector at the SLAC PEP-II asymmetric B Factory during 19992000, we have observed statistically significant signals in the ηc → K SKπ and KKπ channels and set upper limits in the ηc → KKKK channels. All the results presented are preliminary. We have measured B(B → ηcK) = (1.50 ± 0.19 ± 0.15 ± 0.46)×10 B(B → ηcK) = (1.06 ± 0.28 ± 0.11 ± 0.33)×10 where the first error is statistical, the second systematic and the last due to the uncertainty on the world average ηc → KKπ branching fraction. Presented at the XXXVII Rencontres de Moriond on QCD and Hadronic Interactions, 3/16–3/23/2002, Les Arcs, Savoie, France The BABAR Collaboration, B. Aubert, D. Boutigny, J.-M. Gaillard, A. Hicheur, Y. Karyotakis, J. P. Lees, P. Robbe, V. Tisserand, A. Zghiche Laboratoire de Physique des Particules, F-74941 Annecy-le-Vieux, France A. Palano, A. Pompili Università di Bari, Dipartimento di Fisica and INFN, I-70126 Bari, Italy G. P. Chen, J. C. Chen, N. D. Qi, G. Rong, P. Wang, Y. S. Zhu Institute of High Energy Physics, Beijing 100039, China G. Eigen, I. Ofte, B. Stugu University of Bergen, Inst. of Physics, N-5007 Bergen, Norway G. S. Abrams, A. W. Borgland, A. B. Breon, D. N. Brown, J. Button-Shafer, R. N. Cahn, E. Charles, M. S. Gill, A. V. Gritsan, Y. Groysman, R. G. Jacobsen, R. W. Kadel, J. Kadyk, L. T. Kerth, Yu. G. Kolomensky, J. F. Kral, C. LeClerc, M. E. Levi, G. Lynch, L. M. Mir, P. J. Oddone, M. Pripstein, N. A. Roe, A. Romosan, M. T. Ronan, V. G. Shelkov, A. V. Telnov, W. A. Wenzel Lawrence Berkeley National Laboratory and University of California, Berkeley, CA 94720, USA T. J. Harrison, C. M. Hawkes, D. J. Knowles, S. W. O’Neale, R. C. Penny, A. T. Watson, N. K. Watson University of Birmingham, Birmingham, B15 2TT, United Kingdom T. Deppermann, K. Goetzen, H. Koch, B. Lewandowski, K. Peters, H. Schmuecker, M. Steinke Ruhr Universität Bochum, Institut für Experimentalphysik 1, D-44780 Bochum, Germany N. R. Barlow, W. Bhimji, N. Chevalier, P. J. Clark, W. N. Cottingham, B. Foster, C. Mackay, F. F. Wilson University of Bristol, Bristol BS8 1TL, United Kingdom K. Abe, C. Hearty, T. S. Mattison, J. A. McKenna, D. Thiessen University of British Columbia, Vancouver, BC, Canada V6T 1Z1 S. Jolly, A. K. McKemey Brunel University, Uxbridge, Middlesex UB8 3PH, United Kingdom V. E. Blinov, A. D. Bukin, D. A. Bukin, A. R. Buzykaev, V. B. Golubev, V. N. Ivanchenko, A. A. Korol, E. A. Kravchenko, A. P. Onuchin, S. I. Serednyakov, Yu. I. Skovpen, A. N. Yushkov Budker Institute of Nuclear Physics, Novosibirsk 630090, Russia D. Best, M. Chao, D. Kirkby, A. J. Lankford, M. Mandelkern, S. McMahon, D. P. Stoker University of California at Irvine, Irvine, CA 92697, USA K. Arisaka, C. Buchanan, S. Chun University of California at Los Angeles, Los Angeles, CA 90024, USA D. B. MacFarlane, S. Prell, Sh. Rahatlou, G. Raven, V. Sharma University of California at San Diego, La Jolla, CA 92093, USA