Phys. Rev. D
79,
052006
(2009)
[13 pages]
Observation of B0→ΛΛ̅ K0 and B0→ΛΛ̅ K*0 at Belle
Y.-W. Chang et al. Belle Collaboration
Show All Authors/Affiliations
Hide All Authors/Affiliations
Y.-W. Chang26, M.-Z. Wang26, I. Adachi8, H. Aihara43, T. Aushev18,13, A. M. Bakich38, V. Balagura13, A. Bay18, V. Bhardwaj33, U. Bitenc14, A. Bondar1, A. Bozek27, M. Bračko20,14, T. E. Browder7, Y. Chao26, A. Chen24, R. Chistov13, Y. Choi37, J. Dalseno8, M. Danilov13, M. Dash45, A. Drutskoy3, S. Eidelman1, P. Goldenzweig3, H. Ha16, B.-Y. Han16, T. Hara32, K. Hayasaka22, H. Hayashii23, M. Hazumi8, D. Heffernan32, Y. Horii42, Y. Hoshi41, W.-S. Hou26, H. J. Hyun17, K. Inami22, A. Ishikawa34, M. Iwasaki43, Y. Iwasaki8, N. J. Joshi39, D. H. Kah17, J. H. Kang46, H. Kawai2, T. Kawasaki29, H. Kichimi8, H. J. Kim17, Y. I. Kim17, Y. J. Kim5, B. R. Ko16, S. Korpar20,14, P. Križan19,14, Y.-J. Kwon46, S.-H. Kyeong46, J. S. Lee37, M. J. Lee36, S. E. Lee36, T. Lesiak27,4, A. Limosani21, S.-W. Lin26, C. Liu35, Y. Liu5, R. Louvot18, F. Mandl11, A. Matyja27, S. McOnie38, K. Miyabayashi23, H. Miyata29, Y. Miyazaki22, R. Mizuk13, Y. Nagasaka9, M. Nakao8, Z. Natkaniec27, S. Nishida8, O. Nitoh44, S. Ogawa40, S. Okuno15, H. Ozaki8, P. Pakhlov13, G. Pakhlova13, C. W. Park37, H. K. Park17, K. S. Park37, L. S. Peak38, R. Pestotnik14, L. E. Piilonen45, M. Rozanska27, H. Sahoo7, Y. Sakai8, O. Schneider18, A. Sekiya23, K. Senyo22, M. Shapkin12, J.-G. Shiu26, B. Shwartz1, J. B. Singh33, S. Stanič30, M. Starič14, K. Sumisawa8, M. Tanaka8, G. N. Taylor21, Y. Teramoto31, I. Tikhomirov13, S. Uehara8, T. Uglov13, Y. Unno6, S. Uno8, Y. Usov1, G. Varner7, K. Vervink18, C. H. Wang25, P. Wang10, X. L. Wang10, Y. Watanabe15, R. Wedd21, J.-T. Wei26, E. Won16, B. D. Yabsley38, Y. Yamashita28, Z. P. Zhang35, V. Zhilich1, T. Zivko14, A. Zupanc14, and O. Zyukova1 (Belle Collaboration)
1Budker Institute of Nuclear Physics, Novosibirsk
2Chiba University, Chiba
3University of Cincinnati, Cincinnati, Ohio 45221
4T. Kościuszko Cracow University of Technology, Krakow
5The Graduate University for Advanced Studies, Hayama
6Hanyang University, Seoul
7University of Hawaii, Honolulu, Hawaii 96822
8High Energy Accelerator Research Organization (KEK), Tsukuba
9Hiroshima Institute of Technology, Hiroshima
10Institute of High Energy Physics, Chinese Academy of Sciences, Beijing
11Institute of High Energy Physics, Vienna
12Institute of High Energy Physics, Protvino
13Institute for Theoretical and Experimental Physics, Moscow
14J. Stefan Institute, Ljubljana
15Kanagawa University, Yokohama
16Korea University, Seoul
17Kyungpook National University, Taegu
18École Polytechnique Fédérale de Lausanne (EPFL), Lausanne
19Faculty of Mathematics and Physics, University of Ljubljana, Ljubljana
20University of Maribor, Maribor
21University of Melbourne, School of Physics, Victoria 3010
22Nagoya University, Nagoya
23Nara Women’s University, Nara
24National Central University, Chung-li
25National United University, Miao Li
26Department of Physics, National Taiwan University, Taipei
27H. Niewodniczanski Institute of Nuclear Physics, Krakow
28Nippon Dental University, Niigata
29Niigata University, Niigata
30University of Nova Gorica, Nova Gorica
31Osaka City University, Osaka
32Osaka University, Osaka
33Panjab University, Chandigarh
34Saga University, Saga
35University of Science and Technology of China, Hefei
36Seoul National University, Seoul
37Sungkyunkwan University, Suwon
38University of Sydney, Sydney, New South Wales
39Tata Institute of Fundamental Research, Mumbai
40Toho University, Funabashi
41Tohoku Gakuin University, Tagajo
42Tohoku University, Sendai
43Department of Physics, University of Tokyo, Tokyo
44Tokyo University of Agriculture and Technology, Tokyo
45IPNAS, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061
46Yonsei University, Seoul
Received 25 November 2008; published 20 March 2009
We study the charmless decays B→ΛΛ̅ h, where h stands for π+, K+, K0,K*+, or K*0, using a 605 fb-1 data sample collected at the Υ(4S) resonance with the Belle detector at the KEKB asymmetric energy e+e- collider. We observe B0→ΛΛ̅ K0 and B0→ΛΛ̅ K*0 with branching fractions of (4.76-0.68+0.84(stat)±0.61(syst))×10-6 and (2.46-0.72+0.87±0.34)×10-6, respectively. The significances of these signals in the threshold-mass enhanced mass region, MΛΛ̅ <2.85 GeV/c2, are 12.4σ and 9.3σ, respectively. We also update the branching fraction B(B+→ΛΛ̅ K+)=(3.38-0.36+0.41±0.41)×10-6 with better accuracy, and report the following measurement or 90% confidence level upper limit in the threshold-mass-enhanced region: B(B+→ΛΛ̅ K*+)=(2.19-0.88+1.13±0.33)×10-6 with 3.7σ significance; B(B+→ΛΛ̅ π+)<0.94×10-6. A related search for B0→ΛΛ̅ D̅ 0 yields a branching fraction B(B0→ΛΛ̅ D̅ 0)=(1.05-0.44+0.57±0.14)×10-5. This may be compared with the large, ∼10-4, branching fraction observed for B0→pp̅ D̅ 0. The MΛΛ̅ enhancements near threshold and related angular distributions for the observed modes are also reported.
© 2009 The American Physical Society
URL:
http://link.aps.org/doi/10.1103/PhysRevD.79.052006
DOI:
10.1103/PhysRevD.79.052006
|
|
