574 research outputs found
Searches at the Tevatron
No full textResults of searches performed by CDF and D0 are presented. Most of the results are based on data taken during the 1994-95 data taking period (Run I), but some preliminary results from the current data taking period (Run II) are included
Measurement of W pair production in e+ e- collisions at 189-GeV
No full textThe production of W-pairs is analysed in a data samplecollected by ALEPH at a mean centre-of-mass energy of 188.6 GeV,corresponding to an integrated luminosity of 174.2 pb^-1. Crosssections are given for different topologies of W decays intoleptons or hadrons. Combining all final states and assumingStandard Model branching fractions, the total W-pair cross sectionis measured to be 15.71 +- 0.34 (stat) +- 0.18 (syst) pb.Using also the W-pair data samples collected by ALEPH at lowercentre-of-mass energies, the decay branching fraction of the W bosoninto hadrons is measured to be BR (W > hadrons) = 66.97+- 0.65 (stat) +- 0.32 (syst) %, allowing a determination of theCKM matrix element |V(cs)|= 0.951 +- 0.030 (stat) +- 0.015 (syst).The production of W + W − pairs is analysed in a data sample collected by ALEPH at a mean centre-of-mass energy of 188.6 GeV, corresponding to an integrated luminosity of 174.2 pb −1 . Cross sections are given for different topologies of W decays into leptons or hadrons. Combining all final states and assuming Standard Model branching fractions, the total W-pair cross section is measured to be 15.71±0.34 (stat.) ±0.18 (syst.) pb . Using also the W-pair data samples collected by ALEPH at lower centre-of-mass energies, the decay branching fraction of the W boson into hadrons is measured to be B(W→hadrons)=66.97±0.65(stat.)±0.32(syst.)%, allowing a determination of the CKM matrix element | V cs |=0.951±0.030(stat.)±0.015(syst.).The production of W-pairs is analysed in a data sample collected by ALEPH at a mean centre-of-mass energy of 188.6 GeV, corresponding to an integrated luminosity of 174.2 pb^-1. Cross sections are given for different topologies of W decays into leptons or hadrons. Combining all final states and assuming Standard Model branching fractions, the total W-pair cross section is measured to be 15.71 +- 0.34 (stat) +- 0.18 (syst) pb. Using also the W-pair data samples collected by ALEPH at lower centre-of-mass energies, the decay branching fraction of the W boson into hadrons is measured to be BR (W > hadrons) = 66.97 +- 0.65 (stat) +- 0.32 (syst) %, allowing a determination of the CKM matrix element |V(cs)|= 0.951 +- 0.030 (stat) +- 0.015 (syst)
Measurement of W pair production in e+ e- collisions at 183-GeV
No full textThe production of W+W- pairs is analysed in a data sample collected by ALEPH at a mean centre-of-mass energy of 182.7 GeV, corresponding to an integrated luminosity of 57 pb-1. Cross sections are given for different topologies of W decays into leptons or hadrons. Under Standard Model assumptions for the W-pair production and decay, the W-pair cross section is measured to be 15.57+-0.62(stat.)+-0.29(syst.) pb. Using also the W-pair data samples collected by ALEPH at lower centre-of-mass energies, the decay branching ratio of the W boson into hadrons is measured to be B(W->hadrons)= 68.93+-1.21(stat.)+-0.51(syst.)%, allowing a determination of the CKM matrix element |Vcs|= 1.043 +- 0.058(stat.) +- 0.026(syst.). The agreement of the cross sections with the Standard Model prediction allows a limit to be set on the W decay rate to undetectable final states.The production of W+W- pairs is analysed in a data sample collected by ALEPH at a mean centre-of-mass energy of 182.7 GeV, corresponding to an integrated luminosity of 57 pb-1. Cross sections are given for different topologies of W decays into leptons or hadrons. Under Standard Model assumptions for the W-pair production and decay, the W-pair cross section is measured to be 15.57+-0.62(stat.)+-0.29(syst.) pb. Using also the W-pair data samples collected by ALEPH at lower centre-of-mass energies, the decay branching ratio of the W boson into hadrons is measured to be B(W->hadrons)= 68.93+-1.21(stat.)+-0.51(syst.)%, allowing a determination of the CKM matrix element |Vcs|= 1.043 +- 0.058(stat.) +- 0.026(syst.). The agreement of the cross sections with the Standard Model prediction allows a limit to be set on the W decay rate to undetectable final states.The production of W+W- pairs is analysed in a data sample collected by ALEPH at a mean centre-of-mass energy of 182.7 GeV, corresponding to an integrated luminosity of 57 pb-1. Cross sections are given for different topologies of W decays into leptons or hadrons. Under Standard Model assumptions for the W-pair production and decay, the W-pair cross section is measured to be 15.57+-0.62(stat.)+-0.29(syst.) pb. Using also the W-pair data samples collected by ALEPH at lower centre-of-mass energies, the decay branching ratio of the W boson into hadrons is measured to be B(W->hadrons)= 68.93+-1.21(stat.)+-0.51(syst.)%, allowing a determination of the CKM matrix element |Vcs|= 1.043 +- 0.058(stat.) +- 0.026(syst.). The agreement of the cross sections with the Standard Model prediction allows a limit to be set on the W decay rate to undetectable final states.The production of W+W- pairs is analysed in a data sample collected by ALEPH at a mean centre-of-mass energy of 182.7 GeV, corresponding to an integrated luminosity of 57 pb-1. Cross sections are given for different topologies of W decays into leptons or hadrons. Under Standard Model assumptions for the W-pair production and decay, the W-pair cross section is measured to be 15.57+-0.62(stat.)+-0.29(syst.) pb. Using also the W-pair data samples collected by ALEPH at lower centre-of-mass energies, the decay branching ratio of the W boson into hadrons is measured to be B(W->hadrons)= 68.93+-1.21(stat.)+-0.51(syst.)%, allowing a determination of the CKM matrix element |Vcs|= 1.043 +- 0.058(stat.) +- 0.026(syst.). The agreement of the cross sections with the Standard Model prediction allows a limit to be set on the W decay rate to undetectable final states.The production of W+W- pairs is analysed in a data sample collected by ALEPH at a mean centre-of-mass energy of 182.7 GeV, corresponding to an integrated luminosity of 57 pb-1. Cross sections are given for different topologies of W decays into leptons or hadrons. Under Standard Model assumptions for the W-pair production and decay, the W-pair cross section is measured to be 15.57+-0.62(stat.)+-0.29(syst.) pb. Using also the W-pair data samples collected by ALEPH at lower centre-of-mass energies, the decay branching ratio of the W boson into hadrons is measured to be B(W->hadrons)= 68.93+-1.21(stat.)+-0.51(syst.)%, allowing a determination of the CKM matrix element |Vcs|= 1.043 +- 0.058(stat.) +- 0.026(syst.). The agreement of the cross sections with the Standard Model prediction allows a limit to be set on the W decay rate to undetectable final states.The production of W+W- pairs is analysed in a data sample collected by ALEPH at a mean centre-of-mass energy of 182.7 GeV, corresponding to an integrated luminosity of 57 pb-1. Cross sections are given for different topologies of W decays into leptons or hadrons. Under Standard Model assumptions for the W-pair production and decay, the W-pair cross section is measured to be 15.57+-0.62(stat.)+-0.29(syst.) pb. Using also the W-pair data samples collected by ALEPH at lower centre-of-mass energies, the decay branching ratio of the W boson into hadrons is measured to be B(W->hadrons)= 68.93+-1.21(stat.)+-0.51(syst.)%, allowing a determination of the CKM matrix element |Vcs|= 1.043 +- 0.058(stat.) +- 0.026(syst.). The agreement of the cross sections with the Standard Model prediction allows a limit to be set on the W decay rate to undetectable final states.The production of W+W- pairs is analysed in a data sample collected by ALEPH at a mean centre-of-mass energy of 182.7 GeV, corresponding to an integrated luminosity of 57 pb-1. Cross sections are given for different topologies of W decays into leptons or hadrons. Under Standard Model assumptions for the W-pair production and decay, the W-pair cross section is measured to be 15.57+-0.62(stat.)+-0.29(syst.) pb. Using also the W-pair data samples collected by ALEPH at lower centre-of-mass energies, the decay branching ratio of the W boson into hadrons is measured to be B(W->hadrons)= 68.93+-1.21(stat.)+-0.51(syst.)%, allowing a determination of the CKM matrix element |Vcs|= 1.043 +- 0.058(stat.) +- 0.026(syst.). The agreement of the cross sections with the Standard Model prediction allows a limit to be set on the W decay rate to undetectable final states.The production of W+W- pairs is analysed in a data sample collected by ALEPH at a mean centre-of-mass energy of 182.7 GeV, corresponding to an integrated luminosity of 57 pb-1. Cross sections are given for different topologies of W decays into leptons or hadrons. Under Standard Model assumptions for the W-pair production and decay, the W-pair cross section is measured to be 15.57+-0.62(stat.)+-0.29(syst.) pb. Using also the W-pair data samples collected by ALEPH at lower centre-of-mass energies, the decay branching ratio of the W boson into hadrons is measured to be B(W->hadrons)= 68.93+-1.21(stat.)+-0.51(syst.)%, allowing a determination of the CKM matrix element |Vcs|= 1.043 +- 0.058(stat.) +- 0.026(syst.). The agreement of the cross sections with the Standard Model prediction allows a limit to be set on the W decay rate to undetectable final states.The production of W+W- pairs is analysed in a data sample collected by ALEPH at a mean centre-of-mass energy of 182.7 GeV, corresponding to an integrated luminosity of 57 pb-1. Cross sections are given for different topologies of W decays into leptons or hadrons. Under Standard Model assumptions for the W-pair production and decay, the W-pair cross section is measured to be 15.57+-0.62(stat.)+-0.29(syst.) pb. Using also the W-pair data samples collected by ALEPH at lower centre-of-mass energies, the decay branching ratio of the W boson into hadrons is measured to be B(W->hadrons)= 68.93+-1.21(stat.)+-0.51(syst.)%, allowing a determination of the CKM matrix element |Vcs|= 1.043 +- 0.058(stat.) +- 0.026(syst.). The agreement of the cross sections with the Standard Model prediction allows a limit to be set on the W decay rate to undetectable final states.The production of W+W- pairs is analysed in a data sample collected by ALEPH at a mean centre-of-mass energy of 182.7 GeV, corresponding to an integrated luminosity of 57 pb-1. Cross sections are given for different topologies of W decays into leptons or hadrons. Under Standard Model assumptions for the W-pair production and decay, the W-pair cross section is measured to be 15.57+-0.62(stat.)+-0.29(syst.) pb. Using also the W-pair data samples collected by ALEPH at lower centre-of-mass energies, the decay branching ratio of the W boson into hadrons is measured to be B(W->hadrons)= 68.93+-1.21(stat.)+-0.51(syst.)%, allowing a determination of the CKM matrix element |Vcs|= 1.043 +- 0.058(stat.) +- 0.026(syst.). The agreement of the cross sections with the Standard Model prediction allows a limit to be set on the W decay rate to undetectable final states.The production of W+W- pairs is analysed in a data sample collected by ALEPH at a mean centre-of-mass energy of 182.7 GeV, corresponding to an integrated luminosity of 57 pb-1. Cross sections are given for different topologies of W decays into leptons or hadrons. Under Standard Model assumptions for the W-pair production and decay, the W-pair cross section is measured to be 15.57+-0.62(stat.)+-0.29(syst.) pb. Using also the W-pair data samples collected by ALEPH at lower centre-of-mass energies, the decay branching ratio of the W boson into hadrons is measured to be B(W->hadrons)= 68.93+-1.21(stat.)+-0.51(syst.)%, allowing a determination of the CKM matrix element |Vcs|= 1.043 +- 0.058(stat.) +- 0.026(syst.). The agreement of the cross sections with the Standard Model prediction allows a limit to be set on the W decay rate to undetectable final states.The production of W+W- pairs is analysed in a data sample collected by ALEPH at a mean centre-of-mass energy of 182.7 GeV, corresponding to an integrated luminosity of 57 pb-1. Cross sections are given for different topologies of W decays into leptons or hadrons. Under Standard Model assumptions for the W-pair production and decay, the W-pair cross section is measured to be 15.57+-0.62(stat.)+-0.29(syst.) pb. Using also the W-pair data samples collected by ALEPH at lower centre-of-mass energies, the decay branching ratio of the W boson into hadrons is measured to be B(W->hadrons)= 68.93+-1.21(stat.)+-0.51(syst.)%, allowing a determination of the CKM matrix element |Vcs|= 1.043 +- 0.058(stat.) +- 0.026(syst.). The agreement of the cross sections with the Standard Model prediction allows a limit to be set on the W decay rate to undetectable final states.The production of W + W − pairs is analysed in a data sample collected by ALEPH at a mean centre-of-mass energy of 182.7 GeV, corresponding to an integrated luminosity of 57 pb −1 . Cross sections are given for different topologies of W decays into leptons or hadrons. Under Standard Model assumptions for the W-pair production and decay, the W-pair cross section is measured to be 15.57±0.62 (stat.) ±0.29 (syst.) pb . Using also the W-pair data samples collected by ALEPH at lower centre-of-mass energies, the decay branching ratio of the W boson into hadrons is measured to be B(W→hadrons) =68.93±1.21 (stat.) ±0.51 (syst.) % , allowing a determination of the CKM matrix element |V cs |=1.043±0.058 (stat.) ±0.026 (syst.) . The agreement of the cross sections with the Standard Model prediction allows a limit to be set on the W decay rate to undetectable final states
Tau leptonic branching ratios
No full textcomplete author list: Buskulic D.; Casper D.; De Bonis I.; Decamp D.; Ghez P.; Goy C.; Lees J.; Lucotte A.; Minard M.; Odier P.; Pietrzyk B.; Ariztizabal F.; Chmeissani M.; Crespo J.; Efthymiopoulos I.; Fernandez E.; Fernandez-Bosman M.; Gaitan V.; Garrido L.; Martinez M.; Orteu S.; Pacheco A.; Padilla C.; Palla F.; Pascual A.; Perlas J.; Sanchez F.; Teubert F.; Colaleo A.; Creanza D.; De Palma M.; Farilla A.; Gelao G.; Girone M.; Iaselli G.; Maggi G.; Maggi M.; Marinelli N.; Natali S.; Nuzzo S.; Ranieri A.; Raso G.; Romano F.; Ruggieri F.; Selvaggi G.; Silvestris L.; Tempesta P.; Zito G.; Huang X.; Lin J.; Ouyang Q.; Wang T.; Xie Y.; Xu R.; Xue S.; Zhang J.; Zhang L.; Zhao W.; Bonvicini G.; Cattaneo M.; Comas P.; Coyle P.; Drevermann H.; Engelhardt A.; Forty R.; Frank M.; Hagelberg R.; Harvey J.; Jacobsen R.; Janot P.; Jost B.; Kneringer E.; Knobloch J.; Lehraus I.; Markou C.; Martin E.; Mato P.; Minten A.; Miquel R.; Oest T.; Palazzi P.; Pater J.; Pusztaszeri J.; Ranjard F.; Rensing P.; Rolandi L.; Schlatter D.; Schmelling M.; Schneider O.; Tejessy W.; Tomalin I.; Venturi A.; Wachsmuth H.; Wiedenmann W.; Wildish T.; Witzeling W.; Wotschack J.; Ajaltouni Z.; Bardadin-Otwinowska M.; Barres A.; Boyer C.; Falvard A.; Gay P.; Guicheney C.; Henrard P.; Jousset J.; Michel B.; Monteil S.; Montret J.; Pallin D.; Perret P.; Podlyski F.; Proriol J.; Rossignol J.; Saadi F.; Fearnley T.; Hansen J.; Hansen J.; Hansen J.; Hansen P.; Nilsson B.; Kyriakis A.; Simopoulou E.; Siotis I.; Vayaki A.; Zachariadou K.; Blondel A.; Bonneaud G.; Brient J.; Bourdon P.; Passalacqua L.; Rougé A.; Rumpf M.; Tanaka R.; Valassi A.; Verderi M.; Videau H.; Candlin D.; Parsons M.; Focardi E.; Parrini G.; Corden M.; Delfino M.; Georgiopoulos C.; Jaffe D.; Antonelli A.; Bencivenni G.; Bologna G.; Bossi F.; Campana P.; Capon G.; Chiarella V.; Felici G.; Laurelli P.; Mannocchi G.; Murtas F.; Murtas G.; Pepe-Altarelli M.; Dorris S.; Halley A.; Ten Have I.; Knowles I.; Lynch J.; Morton W.; O'Shea V.; Raine C.; Reeves P.; Scarr J.; Smith K.; Smith M.; Thompson A.; Thomson F.; Thorn S.; Turnbull R.; Becker U.; Braun O.; Geweniger C.; Graefe G.; Hanke P.; Hepp V.; Kluge E.; Putzer A.; Rensch B.; Schmidt M.; Sommer J.; Stenzel H.; Tittel K.; Werner S.; Wunsch M.; Beuselinck R.; Binnie D.; Cameron W.; Colling D.; Dornan P.; Konstantinidis N.; Moneta L.; Moutoussi A.; Nash J.; San Martin G.; Sedgbeer J.; Stacey A.; Dissertori G.; Girtler P.; Kuhn D.; Rudolph G.; Bowdery C.; Brodbeck T.; Colrain P.; Crawford G.; Finch A.; Foster F.; Hughes G.; Sloan T.; Whelan E.; Williams M.; Galla A.; Greene A.; Kleinknecht K.; Quast G.; Raab J.; Renk B.; Sander H.; Wanke R.; Van Gemmeren P.; Zeitnitz C.; Aubert J.; Bencheikh A.; Benchouk C.; Bonissent A.; Bujosa G.; Calvet D.; Carr J.; Diaconu C.; Etienne F.; Thulasidas M.; Nicod D.; Payre P.; Rousseau D.; Talby M.; Abt I.; Assmann R.; Bauer C.; Blum W.; Brown D.; Dietl H.; Dydak F.; Ganis G.; Gotzhein C.; Jakobs K.; Kroha H.; Lütjens G.; Lutz G.; Männer W.; Moser H.; Richter R.; Rosado-Schlosser A.; Schael S.; Settles R.; Seywerd H.; St. Denis R.; Wolf G.; Alemany R.; Boucrot J.; Callot O.; Cordier A.; Courault F.; Davier M.; Duflot L.; Grivaz J.; Heusse P.; Jacquet M.; Kim D.; Le Diberder F.; Lefrançois J.; Lutz A.; Musolino G.; Nikolic I.; Park H.; Park I.; Schune M.; Simion S.; Veillet J.; Videau I.; Abbaneo D.; Azzurri P.; Bagliesi G.; Batignani G.; Bettarini S.; Bozzi C.; Calderini G.; Carpinelli M.; Ciocci M.; Ciulli V.; Dell'Orso R.; Fantechi R.; Ferrante I.; Foà L.; Forti F.; Giassi A.; Giorgi M.; Gregorio A.; Ligabue F.; Lusiani A.; Marrocchesi P.; Messineo A.; Rizzo G.; Sanguinetti G.; Sciabà A.; Spagnolo P.; Steinberger J.; Tenchini R.; Tonelli G.; Triggiani G.; Vannini C.; Verdini P.; Walsh J.; Betteridge A.; Blair G.; Bryant L.; Cerutti F.; Gao Y.; Green M.; Johnson D.; Medcalf T.; Mir L.; Perrodo P.; Strong J.; Bertin V.; Botterill D.; Clifft R.; Edgecock T.; Haywood S.; Edwards M.; Maley P.; Norton P.; Thompson J.; Bloch-Devaux B.; Colas P.; Emery S.; Kozanecki W.; Lançon E.; Lemaire M.; Locci E.; Marx B.; Perez P.; Rander J.; Renardy J.; Roussarie A.; Schuller J.; Schwindling J.; Trabelsi A.; Vallage B.; Johnson R.; Kim H.; Litke A.; McNeil M.; Taylor G.; Beddall A.; Booth C.; Boswell R.; Cartwright S.; Combley F.; Dawson I.; Koksal A.; Letho M.; Newton W.; Rankin C.; Thompson L.; B̈ohrer A.; Brandt S.; Cowan G.; Feigl E.; Grupen C.; Lutters G.; Minguet-Rodriguez J.; Rivera F.; Saraiva P.; Smolik L.; Stephan F.; Apollonio M.; Bosisio L.; Della Marina R.; Giannini G.; Gobbo B.; Ragusa F.; Rothberg J.; Wasserbaech S.; Armstrong S.; Bellantoni L.; Elmer P.; Feng Z.; Ferguson D.; Gao Y.; González S.; Grahl J.; Harton J.; Hayes O.; Hu H.; McNamara P.; Nachtman J.; Orejudos W.; Pan Y.; Saadi Y.; Schmitt M.; Scott I.; Sharma V.; Turk J.; Walsh A.; Wu S.; Wu X.; Yamartino J.; Zheng M.; Zobernig G.; Casper D.; Buskulic D.; Zobernig G.; Zheng M.; Yamartino J.; Wu X.; Wu S.; Walsh A.; Turk J.; Sharma V.; Scott I.; Schmitt M.; Saadi Y.; Pan Y.; Orejudos W.; Buskulic D.</p
Measurement of the polar-angle distribution of leptons from W boson decay as a function of the W transverse momentum in p(p)over-bar collisions ar root s=1.8 TeV
No full textWe present a measurement of the polar-angle distribution of leptons from W boson decay, as a function of the W transverse momentum. The measurement uses an 80+/-4 pb(-1) sample of p (p) over bar collisions at roots=1.8 TeV collected by the CDF detector and includes data from both the W--\u3ee+nu and W--\u3emu+nu decay channels. We fit the W boson transverse mass distribution to a set of templates from a Monte Carlo event generator and detector simulation in several ranges of the W transverse momentum. The measurement agrees with the standard model expectation, whereby the ratio of longitudinally to transversely polarized W bosons, in the Collins-Soper W rest frame, increases with the W transverse momentum at a rate of approximately 15% per 10 GeV/c
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