218 articles – 617 Notices  [english version]
 HAL : in2p3-00021883, version 1
 European Physical Journal C 35 (2004) 35-52
 Search for $B_{s}^{0}_\overline{B_{s}^{0}}$ oscillations in DELPHI using high-$p_{t}$ leptons
 DELPHI Collaboration(s)
 (2004)
 Oscillations in the B0_s - anti-B0_s system were studied in events selected from about 4.3 million hadronic Z^0 decays registered by DELPHI between 1992 and 2000. This paper presents updates of two published analyses ([11,12]). The first analysis, which utilizes leptons emitted with large momentum transverse to a jet, was improved by means of a better algorithm for the vertex reconstuction and a new algorithm for flavour-tagging at production time. The second analysis, which utilizes D_s-lepton events, was improved by optimizing the treatment of proper time resolution. No signal of B0_s oscillations was observed and limits on the mass difference between the physical B0_s states were obtained to be: \Delta m_s > 8.0 ps^{-1} at the 95% C.L. with a sensitivity of \Delta m_s = 9.1 ps^{-1} in the high p_t lepton analysis and \Delta m_s > 4.9 ps^{-1} at the 95% C.L. with a sensitivity of \Delta m_s = 8.6 ps^{-1} in the D_s-lepton analysis. Previously published results on these analyses are superseed. The combination of these results with those obtained in other independent analyses previously performed in DELPHI (D_s-hadron, exclusive B0_s, inclusive vertex) gives: \Delta m_s > 8.5 ps^{-1} at the 95% C.L. with a sensitivity of \Delta m_s = 12.0 ps^{-1}.
 Thème(s) : Physique/Physique des Hautes Energies - Expérience
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 in2p3-00021883, version 1 http://hal.in2p3.fr/in2p3-00021883 oai:hal.in2p3.fr:in2p3-00021883 Contributeur : Emmanuelle Vernay <> Soumis le : Lundi 7 Juin 2004, 14:41:11 Dernière modification le : Lundi 22 Mai 2006, 14:41:34