Observation of the narrow state X(3872) → J/ψπ+π- in p̄p collisions at √s = 1.96 TeV
Physical Review Letters 93:7 (2004)
Abstract:
The observation of a state consistent with X(3872) decaying into J/ψπ+π- was reported. The X(3872) mass was measured to be 3871.3±0.7(stat)±0.4(syst)MeV/c2 from a sample of 730±90 candidates. The observed width was consistent with the detector resolution. The results were found to be converging well with the measurements by the Belle Collaboration using b± decays.Performance of Hamamatsu 64-anode photomultipliers for use with wavelength--shifting optical fibres
ArXiv physics/0408055 (2004)
Search for Bs 0 → μ+μ - and Bd 0 → μ+μ - decays in pp̄ collisions at √s = 1.96 TeV
Physical Review Letters 93:3 (2004)
Abstract:
The decay mechanisms of Bs0 → μ +μ- and Bd0 → μ +μ- in pp̄ collisions were investigated. For discrimination of the decays from background events, four variables were used such as invariant mass of muon pair, B-candidate proper decay length, opening angle between B-hadron flight direction and B-candidate track isolation. A 'blind' analysis technique was also used for determination of optimal selection criteria for four variables. The results show that optimal set of selection criteria uses ∓80 MeV/c2 search window around B s0 mass, and I > 0.65.Search for narrow tt̄ Resonances in pp̄ collisions at √s = 1.8 Te V
Physical Review Letters 92:22 (2004)
Abstract:
A search for narrow resonances decaying to tt̄ pairs was carried out. No significant deviation was observed from the standard-model predictions at a top-quark mass of 175 GeV/c2. Upper limits were established at the 95% confidence level on the product of the production cross section and branching fraction to tt̄ for narrow resonances as a function of the resonance mass Mx. The existence of a leptophobic top-color particle with mass Mx<560 GeV/c2 was excluded for a width T x = 0.012Mx.Search for pair production of light scalar top quarks in pp collisions at √s = 1.8 TeV
Physical Review Letters 93:1 (2004)