1207.6244 (Belle Collaboration et al.)

Evidence for B- ? Ds+ K- l- nubar and search for B- ? Ds*+ K- l- nubar    [PDF]

Belle Collaboration, J. Stypula, M. Rozanska, I. Adachi, K. Adamczyk, H. Aihara, D. M. Asner, T. Aushev, A. M. Bakich, V. Bhardwaj, B. Bhuyan, M. Bischofberger, A. Bondar, G. Bonvicini, A. Bozek, M. Bra\v, T. E. Browder, M. -C. Chang, P. Chang, V. Chekelian, A. Chen, P. Chen, B. G. Cheon, R. Chistov, I. -S. Cho, K. Cho, Y. Choi, J. Dalseno, M. Danilov, J. Dingfelder, Z. Dole\v, Z. Drásal, A. Drutskoy, S. Eidelman, H. Farhat, J. E. Fast, V. Gaur, N. Gabyshev, R. Gillard, Y. M. Goh, B. Golob, J. Haba, K. Hayasaka, H. Hayashii, Y. Horii, Y. Hoshi, W. -S. Hou, Y. B. Hsiung, H. J. Hyun, T. Iijima, K. Inami, A. Ishikawa, R. Itoh, M. Iwabuchi, Y. Iwasaki, T. Julius, J. H. Kang, P. Kapusta, T. Kawasaki, H. Kichimi, C. Kiesling, H. J. Kim, J. B. Kim, J. H. Kim, K. T. Kim, Y. J. Kim, K. Kinoshita, B. R. Ko, P. Kody\v, S. Korpar, R. T. Kouzes, P. Kri\v, P. Krokovny, T. Kuhr, T. Kumita, A. Kuzmin, Y. -J. Kwon, S. -H. Lee, J. Li, Y. Li, J. Libby, C. Liu, Y. Liu, Z. Q. Liu, D. Liventsev, R. Louvot, K. Miyabayashi, H. Miyata, Y. Miyazaki, R. Mizuk, G. B. Mohanty, A. Moll, N. Muramatsu, E. Nakano, Z. Natkaniec, C. Ng, S. Nishida, K. Nishimura, O. Nitoh, T. Nozaki, S. Ogawa, T. Ohshima, S. Okuno, S. L. Olsen, Y. Onuki, P. Pakhlov, G. Pakhlova, C. W. Park, H. Park, H. K. Park, T. K. Pedlar, R. Pestotnik, M. Petri\v, L. E. Piilonen, M. Ritter, M. Röhrken, S. Ryu, H. Sahoo, Y. Sakai, S. Sandilya, D. Santel, T. Sanuki, Y. Sato, O. Schneider, C. Schwanda, K. Senyo, O. Seon, M. E. Sevior, M. Shapkin, C. P. Shen, T. -A. Shibata, J. -G. Shiu, A. Sibidanov, F. Simon, P. Smerkol, Y. -S. Sohn, A. Sokolov, E. Solovieva, S. Stani\v, M. Stari\v, M. Sumihama, T. Sumiyoshi, Y. Teramoto, M. Uchida, T. Uglov, Y. Unno, S. Uno, P. Urquijo, Y. Usov, P. Vanhoefer, G. Varner, K. E. Varvell, V. Vorobyev, P. Wang, X. L. Wang, M. Watanabe, Y. Watanabe, K. M. Williams, E. Won, B. D. Yabsley, H. Yamamoto, Y. Yamashita, Z. P. Zhang, V. Zhilich, V. Zhulanov, A. Zupanc

We report measurements of the decays B- \rightarrow Ds(*)+ K- l- nubar in a data sample containing 657x10^6 BBbar pairs collected with the Belle detector at the KEKB asymmetric-energy e+e- collider. We observe a signal with a significance of 6 sigma for the combined Ds and Ds* modes and find the first evidence of the B- \rightarrow Ds+ K- l- nubar decay with a significance of 3.4 sigma. We measure the following branching fractions: BF(B- \rightarrow Ds+ K- l nubar) = (0.30 +/- 0.09(stat) +0.11 -0.08(syst)) x 10^-3 and BF(B- \rightarrow Ds*+ K- l- nubar) = (0.59 +/- 0.12(stat) +/- 0.15(syst)) x 10^-3 and set an upper limit BF(B- \rightarrow Ds*+ K- l- nubar) < 0.56 x 10^-3 at the 90% confidence level. We also present the first measurement of the Ds+K- invariant mass distribution in these decays, which is dominated by a prominent peak around 2.6 GeV/c^2.

View original: http://arxiv.org/abs/1207.6244