Using approximately 4 million hadronic Z decays recorded with the ALEPH detector from 1991 through 1995, the lifetime of the b baryon is measured with three independent methods. From the impact parameter distribution of candidate leptons in 1063 events with Lambda l(-) combinations, the average b baryon lifetime is measured to be 1.20 +/- 0.08 +/- 0.06 ps. From a sample of 193 fully reconstructed Lambda(c)(+) candidates correlated with a lepton and a sample of 46 Lambda l(+)l(-) combinations the Lambda(b) lifetime is measured to be 1.21+/-0.11 ps. The product branching fractions to these final states are Br(b-->Lambda(b)) . Br(Lambda(b) --> Lambda l(-)(v) over bar X) = 0.326 +/- 0.016 +/- 0.039% for the first sample and Br(b --> Lambda(b)) . Br(Lambda(b) --> Lambda(c)(+)l(-)(v) over bar X) = 0.86 +/- 0.07 +/- 0.14% for the second and third samples combined.
Measurement of the b baryon lifetime and branching fractions in Z decays / R. Barate, D. Buskulic, D. Decamp, P. Ghez, G. Goy, J. Lees, A. Lucotte, M. Minard, J. Nief, B. Pietrzyk, M. Casado, M. Chmeissani, P. Comas, J. Crespo, M. Delfino, E. Fernandez, M. Fernandez-Bosman, L. Garrido, A. Juste, M. Martinez, G. Merino, R. Miquel, L. Mir, C. Padilla, I. Park, A. Pascual, J. Perlas, I. Riu, F. Sanchez, A. Colaleo, D. Creanza, M. de Palma, G. Gelao, G. Iaselli, G. Maggi, M. Maggi, N. Marinelli, S. Nuzzo, A. Ranieri, G. Raso, F. Ruggieri, G. Selvaggi, L. Silvestris, P. Tempesta, A. Tricomi, G. Zito, X. Huang, J. Lin, Q. Ouyang, T. Wang, Y. Xie, R. Xu, S. Xue, J. Zhang, L. Zhang, W. Zhao, D. Abbaneo, R. Alemany, U. Becker, A. Bazarko, P. Bright-Thomas, M. Cattaneo, F. Cerutti, G. Dissertori, H. Drevermann, R. Forty, M. Frank, R. Hagelberg, J. Hansen, J. Harvey, P. Janot, B. Jost, E. Kneringer, J. Knobloch, I. Lehraus, P. Mato, A. Minten, L. Moneta, A. Pacheco, J. Pusztaszeri, F. Ranjard, G. Rizzo, L. Rolandi, D. Rousseau, D. Schlatter, M. Schmitt, O. Schneider, W. Tejessy, F. Teubert, I. Tomalin, H. Wachsmuth, A. Wagner, Z. Ajaltouni, A. Barres, C. Boyer, A. Falvard, C. Ferdi, P. Gay, C. Guicheney, P. Henrard, J. Jousset, B. Michel, S. Monteil, J. Montret, D. Pallin, P. Perret, F. Podlyski, J. Proriol, P. Rosnet, J. Rossignol, T. Fearnley, J. Hansen, J. Hansen, P. Hansen, B. Nilsson, B. Rensch, A. Waananen, G. Daskalakis, A. Kyriakis, C. Markou, E. Simopoulou, I. Siotis, A. Vayaki, A. Blondel, G. Bonneaud, J. Brient, P. Bourdon, A. Rouge, M. Rumpf, A. Valassi, M. Verderi, H. Videau, D. Candlin, M. Parsons, E. Focardi, G. Parrini, K. Zachariadou, M. Corden, C. Georgiopoulos, D. Jaffe, A. Antonelli, G. Bencivenni, G. Bologna, F. Bossi, P. Campana, G. Capon, D. Casper, V. Chiarella, G. Felici, P. Laurelli, G. Mannocchi, F. Murtas, G. Murtas, L. Passalacqua, M. Pepe-Altarelli, L. Curtis, S. Dorris, A. Halley, I. Knowles, J. Lynch, V. O'Shea, C. Raine, J. Scarr, K. Smith, P. Teixeira-Dias, A. Thompson, E. Thomson, F. Thomson, R. Turnbull, O. Buchmuller, S. Dhamotharan, C. Geweniger, G. Graefe, P. Hanke, G. Hansper, V. Hepp, E. Kluge, A. Putzer, J. Sommer, K. Tittel, S. Werner, M. Wunsch, R. Beuselinck, D. Binnie, W. Cameron, P. Dornan, M. Girone, S. Goodsir, E. Martin, A. Moutoussi, J. Nash, J. Sedgbeer, P. Spagnolo, A. Stacey, M. Williams, V. Ghete, P. Girtler, D. Kuhn, G. Rudolph, A. Betteridge, C. Bowdery, P. Buck, P. Colrain, G. Crawford, A. Finch, F. Foster, G. Hughes, R. Jones, T. Sloan, M. Williams, I. Giehl, A. Greene, C. Hoffmann, K. Jakobs, K. Kleinknecht, G. Quast, B. Renk, E. Rohne, H. Sander, P. van Gemmeren, C. Zeitnitz, J. Aubert, C. Benchouk, A. Bonissent, G. Bujosa, J. Carr, P. Coyle, C. Diaconu, F. Etienne, N. Konstantinidis, O. Leroy, F. Motsch, P. Payre, M. Talby, A. Sadouki, M. Thulasidas, K. Trabelsi, M. R.A. Aleppo, M. Antonelli, F. Ragusa, R. Berlich, W. Blum, V. Buscher, H. Dietl, G. Ganis, C. Gotzhein, H. Kroha, G. Lutjens, G. Lutz, W. Manner, H. Moser, R. Richter, A. Rosado-Schlosser, S. Schael, R. Settles, H. Seywerd, R. St Denis, H. Stenzel, W. Wiedenmann, G. Wolf, J. Boucrot, O. Callot, S. Chen, Y. Choi, A. Cordier, M. Davier, L. Duflot, J. Grivaz, P. Heusse, A. Hocker, A. Jacholkowska, M. Jacquet, D. Kim, F. Le Diberder, J. Lefrancois, A. Lutz, I. Nikolic, M. Schune, S. Simion, E. Tournefier, J. Veillet, I. Videau, D. Zerwas, P. Azzurri, G. Bagliesi, G. Batignani, S. Bettarini, C. Bozzi, G. Calderini, M. Carpinelli, M. Ciocci, V. Ciulli, R. Dell'Orso, N. Fantechi, I. Ferrante, L. Foa, F. Forti, A. Giassi, M. Giorgi, A. Gregorio, F. Ligabue, A. Lusiani, P. Marrocchesi, A. Messineo, F. Palla, G. Sanguinetti, A. Sciaba, J. Steinberger, R. Tenchini, G. Tonelli, C. Vannini, A. Venturi, P. Verdini, G. Blair, L. Bryant, J. Chambers, Y. Gao, M. Green, T. Medcalf, P. Perrodo, J. Strong, J. von Wimmersperg-Toeller, D. Botterill, R. Clifft, T. Edgecock, S. Haywood, P. Norton, J. Thompson, A. Wright, B. Bloch-Devaux, P. Colas, S. Emery, W. Kozanecki, E. Lancon, M. Lemaire, E. Locci, P. Perez, J. Rander, J. Renardy, A. Roussarie, J. Schuller, J. Schwindling, A. Trabelsi, B. Vallage, S. Black, J. Dann, R. Johnson, H. Kim, A. Litke, M. McNeil, G. Taylor, C. Booth, R. Boswell, C. Brew, S. Cartwright, F. Combley, M. Kelly, M. Lehto, W. Newton, J. Reeve, L. Thompson, A. Bohrer, S. Brandt, G. Cowan, C. Grupen, G. Lutters, P. Saraiva, L. Smolik, F. Stephan, M. Apollonio, L. Bosisio, R. Della Marina, G. Giannini, B. Gobbo, G. Musolino, J. Rothberg, S. Wasserbaech, S. Armstrong, E. Charles, P. Elmer, D. Ferguson, S. Gonzalez, T. Greening, O. Hayes, H. Hu, S. Jin, P. McNamara, J. Nachtman, J. Nielsen, W. Orejudos, Y. Pan, Y. Saadi, I. Scott, J. Walsh, S. Wu, X. Wu, J. Yamartino, G. Zobernig. - In: THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS. - ISSN 1434-6044. - 2:2(1998), pp. 197-211. [10.1007/s100520050133]
Measurement of the b baryon lifetime and branching fractions in Z decays
M. R.A. Aleppo;F. Ragusa;
1998
Abstract
Using approximately 4 million hadronic Z decays recorded with the ALEPH detector from 1991 through 1995, the lifetime of the b baryon is measured with three independent methods. From the impact parameter distribution of candidate leptons in 1063 events with Lambda l(-) combinations, the average b baryon lifetime is measured to be 1.20 +/- 0.08 +/- 0.06 ps. From a sample of 193 fully reconstructed Lambda(c)(+) candidates correlated with a lepton and a sample of 46 Lambda l(+)l(-) combinations the Lambda(b) lifetime is measured to be 1.21+/-0.11 ps. The product branching fractions to these final states are Br(b-->Lambda(b)) . Br(Lambda(b) --> Lambda l(-)(v) over bar X) = 0.326 +/- 0.016 +/- 0.039% for the first sample and Br(b --> Lambda(b)) . Br(Lambda(b) --> Lambda(c)(+)l(-)(v) over bar X) = 0.86 +/- 0.07 +/- 0.14% for the second and third samples combined.Pubblicazioni consigliate
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.