In a data sample of approximately four million hadronic Z decays recorded with the ALEPH detector from 1990 to 1995, a search for the strange b baryon Ξb is performed with a study of Ξ-lepton correlations. Forty-four events with same sign Ξ−ℓ− combinations are found whereas 8.4 are expected based on the rate of opposite sign Ξ−ℓ+ combinations. This significant excess is interpreted as evidence for Ξb semileptonic decays. The measured product branching ratio is View the MathML source per lepton species, averaged over electrons and muons, with Xc a charmed baryon. The Ξb lifetime is measured to be τΞb = 1.35−0.28+0.37(stat)−0.17+0.15(syst) ps.
Strange b baryon production and lifetime in Z decays / D. Buskulic;I. De Bonis;D. Decamp;P. Ghez;C. Goy;J.-P. Lees;A. Lucotte;M.-N. Minard;J.-Y. Nief;P. Odier;B. Pietrzyk;M.P. Casado;M. Chmeissani;J.M. Crespo;M. Delfino;I. Efthymiopoulos;E. Fernandez;M. Fernandez-Bosman;Ll. Garrido;A. Juste;M. Martinez;S. Orteu;C. Padilla;I.C. Park;A. Pascual;J.A. Perlas;I. Riu;F. Sanchez;F. Teubert;A. Colaleo;D. Creanza;M. de Palma;G. Gelao;M. Girone;G. Iaselli;G. Maggi;M. Maggi;N. Marinelli;S. Nuzzo;A. Ranieri;G. Raso;F. Ruggieri;G. Selvaggi;L. Silvestris;P. Tempesta;G. Zito;X. Huang;J. Lin;Q. Ouyang;T. Wang;Y. Xie;R. Xu;S. Xue;J. Zhang;L. Zhang;W. Zhao;R. Alemany;A.O. Bazarko;G. Bonvicini;M. Cattaneo;P. Comas;P. Coyle;H. Drevermann;R.W. Forty;M. Frank;R. Hagelberg;J. Harvey;P. Janot;B. Jost;E. Kneringer;J. Knobloch;I. Lehraus;G. Lutters;E.B. Martin;P. Mato;A. Minten;R. Miquel;Ll.M. Mir;L. Moneta;T. Oest;A. Pacheco;J.-F. Pusztaszeri;F. Ranjard;P. Rensing;L. Rolandi;D. Schlatter;M. Schmelling;M. Schmitt;O. Schneider;W. Tejessy;I.R. Tomalin;A. Venturi;H. Wachsmuth;A. Wagner;Z. Ajaltouni;A. Barrès;C. Boyer;A. Falvard;P. Gay;C. Guicheney;P. Henrard;J. Jousset;B. Michel;S. Monteil;J-C. Montret;D. Pallin;P. Perret;F. Podlyski;J. Proriol;P. Rosnet;J.-M. Rossignol;T. Fearnley;J.B. Hansen;J.D. Hansen;J.R. Hansen;P.H. Hansen;B.S. Nilsson;B. Rensch;A. Wäänänen;A. Kyriakis;C. Markou;E. Simopoulou;I. Siotis;A. Vayaki;K. Zachariadou;A. Blondel;G. Bonneaud;J.C. Brient;P. Bourdon;A. Rougé;M. Rumpf;A. Valassi;M. Verderi;H. Videau;D.J. Candlin;M.I. Parsons;E. Focardi;G. Parrini;M. Corden;C. Georgiopoulos;D.E. 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.P. Murtas;L. Passalacqua;M. Pepe-Altarelli;L. Curtis;S.J. Dorris;A.W. Halley;I.G. Knowles;J.G. Lynch;V. O'Shea;C. Raine;P. Reeves;J.M. Scarr;K. Smith;P. Teixeira-Dias;A.S. Thompson;F. Thomson;S. Thorn;R.M. Turnbull;U. Becker;C. Geweniger;G. Graefe;P. Hanke;G. Hansper;V. Hepp;E.E. Kluge;A. Putzer;M. Schmidt;J. Sommer;H. Stenzel;K. Tittel;S. Werner;M. Wunsch;D. Abbaneo;R. Beuselinck;D.M. Binnie;W. Cameron;P.J. Dornan;A. Moutoussi;J. Nash;J.K. Sedgbeer;A.M. Stacey;M.D. Williams;G. Dissertori;P. Girtler;D. Kuhn;G. Rudolph;A.P. Betteridge;C.K. Bowdery;P. Colrain;G. Crawford;A.J. Finch;F. Foster;G. Hughes;T. Sloan;M.I. Williams;A. Galla;I. Giehl;A.M. Greene;K. Kleinknecht;G. Quast;B. Renk;E. Rohne;H.-G. Sander;P. van Gemmeren;C. Zeitnitz;J.J. Aubert;A.M. Bencheikh;C. Benchouk;A. Bonissent;G. Bujosa;D. Calvet;J. Carr;C. Diaconu;F. Etienne;N. Konstantinidis;P. Payre;D. Rousseau;M. Talby;A. Sadouki;M. Thulasidas;K. Trabelsi;M. Aleppo;F. Ragusa;I. Abt;R. Assmann;C. Bauer;W. Blum;H. Dietl;F. Dydak;G. Ganis;C. Gotzhein;K. Jakobs;H. Kroha;G. Lütjens;G. Lutz;W. Männer;H.-G. Moser;R. Richter;A. Rosado-Schlosser;S. Schael;R. Settles;H. Seywerd;R.St. Denis;W. Wiedenmann;G. Wolf;J. Boucrot;O. Callot;Y. Choi;A. Cordier;M. Davier;L. Duflot;J.-F. Grivaz;Ph. Heusse;A. Höcker;A. Jacholkowska;M. Jacquet;D.W. Kim;F. Le Diberder;J. Lefrançois;A.-M. Lutz;I. Nikolic;H.J. Park;M.-H. Schune;S. Simion;J.-J. Veillet;I. Videau;D. Zerwas;P. Azzurri;G. Bagliesi;G. Batignani;S. Bettarini;C. Bozzi;G. Calderini;M. Carpinelli;M.A. Ciocci;V. Ciulli;R. Dell'Orso;R. Fantechi;I. Ferrante;L. Foà;F. Forti;A. Giassi;M.A. Giorgi;A. Gregorio;F. Ligabue;A. Lusiani;P.S. Marrocchesi;A. Messineo;F. Palla;G. Rizzo;G. Sanguinetti;A. Sciabà;P. Spagnolo;J. Steinberger;R. Tenchini;G. Tonelli;C. Vannini;P.G. Verdini;J. Walsh;G.A. Blair;L.M. Bryant;F. Cerutti;J.T. Chambers;Y. Gao;M.G. Green;T. Medcalf;P. Perrodo;J.A. Strong;J.H. von Wimmersperg-Toeller;D.R. Botterill;R.W. Clifft;T.R. Edgecock;S. Haywood;P. Maley;P.R. Norton;J.C. Thompson;A.E. Wright;B. Bloch-Devaux;P. Colas;S. Emery;W. Kozanecki;E. Lançon;M.C. Lemaire;E. Locci;B. Marx;P. Perez;J. Rander;J.-F. Renardy;A. Roussarie;J.-P. Schuller;J. Schwindling;A. Trabelsi;B. Vallage;S.N. Black;J.H. Dann;R.P. Johnson;H.Y. Kim;A.M. Litke;M.A. McNeil;G. Taylor;C.N. Booth;R. Boswell;C.A.J. Brew;S. Cartwright;F. Combley;A. Koksal;M. Letho;W.M. Newton;J. Reeve;L.F. Thompson;A. Böhrer;S. Brandt;V. Büscher;G. Cowan;C. Grupen;J. Minguet-Rodriguez;F. Rivera;P. Saraiva;L. Smolik;F. Stephan;M. Apollonio;L. Bosisio;R.Della Marina;G. Giannini;B. Gobbo;G. Musolino;J. Rothberg;S. Wasserbaech;S.R. Armstrong;P. Elmer;Z. Feng;D.P.S. Ferguson;Y.S. Gao;S. González;J. Grahl;T.C. Greening;O.J. Hayes;H. Hu;P.A. McNamara;J.M. Nachtman;W. Orejudos;Y.B. Pan;Y. Saadi;I.J. Scott;A.M. Walsh;Sau Lan Wu;X. Wu;J.M. Yamartino;M. Zheng;G. Zobernig. - In: PHYSICS LETTERS. SECTION B. - ISSN 0370-2693. - ELETTRONICO. - 384:(1996), pp. 449-460. [10.1016/0370-2693(96)00925-2]
Strange b baryon production and lifetime in Z decays
FOCARDI, ETTORE;CIULLI, VITALIANO;
1996
Abstract
In a data sample of approximately four million hadronic Z decays recorded with the ALEPH detector from 1990 to 1995, a search for the strange b baryon Ξb is performed with a study of Ξ-lepton correlations. Forty-four events with same sign Ξ−ℓ− combinations are found whereas 8.4 are expected based on the rate of opposite sign Ξ−ℓ+ combinations. This significant excess is interpreted as evidence for Ξb semileptonic decays. The measured product branching ratio is View the MathML source per lepton species, averaged over electrons and muons, with Xc a charmed baryon. The Ξb lifetime is measured to be τΞb = 1.35−0.28+0.37(stat)−0.17+0.15(syst) ps.I documenti in FLORE sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.