| Autor: |
Veikko Karimäki, Emilio Petrolo, E. Pietarinen, Daniel Denegri, H. Teykal, Jean-Pierre Merlo, Felicitas Pauss, M. Rauschkolb, R. Prosi, Pierluigi Zotto, Filippo Ceradini, A. Diciaccio, C. Demoulin, T. A. Fuess, C. Rubbia, J. Dorenbosch, A. Caner, M. Markytan, A. Bezaguet, J M. Salicio, B. Gonzalez, L. Taylor, H. Faissner, J. Gronberg, S. Levegrün, D. H. Stork, X. Wu, D. J. Holthuizen, P. Cennini, S. Otwinowski, Tejinder Virdee, Stefano Veneziano, M. Yvert, R. Priem, W. von Schlippe, P. Nedelec, Francesco Lacava, H. Dibon, A. Moulin, C. Markou, R. Martinelli, G. Sajot, I. F. Fensome, H. Bohn, Sergio Cittolin, Peter Lipa, S. Tether, D. Schinzel, A. Ferrando, D. Schleichert, E. Torrente-Lujan, J. P. Revol, Carmen Albajar, Aleandro Nisati, M. Passaseo, S. Centro, Jorma Tuominiemi, Nicolas Ellis, Alessandro Bettini, F. Szoncso, M.I. Josa, K. Wacker, Christopher Seez, J.P. Vialle, D. Samyn, Ludovico Pontecorvo, C. Daum, G. Pancheri, M. Mohammadi, A. Böhrer, C.-E. Wulz, J. Colas, G. Thompson, A. Morsch, D. Kryn, V. O'Dell, K. Eggert, D. Dau, M. Della Negra, Manfred Krammer, O. C. Allkofer, H. Evans, G. Ciapetti, R. Conte, D. Brockhausen, A. van Dijk, Steve McMahon, P. Casoli, G. Busetto, Konstanty Sumorok, Anton Taurok, Alain Givernaud, E. Eisenhandler, J. Garvey, Paraskevas Sphicas, T. Moers, I. Zacharov, K. Morgan, M. Vargas, I. R. Kenyon, A. Norton, F. Cavanna, L. Naumann, M. Botlo, M. Nikitas, D. Drijard, F. J. Diez Hedo, G. Piano Mortari, G. Bauer, M. Felcini, Teresa Rodrigo, A. Geiser, P. I. P. Kalmus, G. Maurin, S. Bartha, W. van de Guchte, P. Biddulph, M. Pimiä, M. A. Marquina, C. Bacci, K. Bos, R. Bonino, Y. Lemoigne, Th. Müller, W. Jank, Matthias Schröder, K. Ankoviak, Ritva Kinnunen, A. Bushbeck, L. Dobrzynski, David B. Cline, D. Linglin, T. C. Meyer, M. P. J. Landon, John A Coughlan, H. Tuchscherer, L. Fortson, James Rohlf, E. Radermacher, G. Jorat, Claudia J. Stubenrauch, S. Lammel, A. Gonidec, Jonathan M. Gregory, C.H. Tan, R. Apsimon, R. Munoz, Michael Albrow, H. Wagner, Dave Robinson, A. Placci, J. Vrana, L. Zanello, B. Aubert, Hans Reithler, E. F. Clayton, J. P. Porte, Y. Zolnierowski, C. D. Buchanan, T. P. Shah, V. Vuillemin, H. Castilla-Valdez, J. D. Dowell, J. P. Mendiburu, Anna Teresa Meneguzzo |
| Rok vydání: |
1991 |
| Předmět: |
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| Popis: |
We report on the first observation of the beauty baryon Λb in an exclusive decay channel at the CERN p p collider. Using 4.7 pb−1 of muon data collected in the 1988/89 collider runs we reconstruct 16±5 Λb's in the decay mode Λ b → J ψΛ above a background of 9±1 events, corresponding to a significance of about five standard deviations. We measure the Λb mass to be mΛb=5640±50±30 MeV/c2. Using the beauty cross-section measured by UA1 we deduce for the product of the production fraction and branching ratio f Λ b Br (Λ b → J ψΛ )=(1.8±1.0)×10 -10 . Our sample contains three-muon event in which the beauty particle opposite to the Λ b is tagged by the third muon. We also observe an indication of a signal in the decay channel B 0 → J ψ K 0∗ with a significance of three standard deviations. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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