Accelerator Neutrinos

Abstract:

We report on the reconstruction of the decay mode B0→J/ΨKS0 using 19.3pb-1 of data collected by the Collider Detector at Fermilab in p-p collisions at √s=1.8TeV. A signal of 41.8±6.9 events, with a signal-to-background ratio of 9:1, is observed. Three additional decay modes B+→J/ΨK+, B0→J/ΨK*(892)0, and B+→J/ΨK*(892)+ are reconstructed. We measure three ratios of branching ratios, each one relative to the B+→J/ΨK+ mode. We also report the ratio of decay rates, γ(B→J/ΨK*)/γ(B→J/ΨK), for the vector-vector relative to the vector-pseudoscalar modes, to be 1.32±0.23(stat)±0.16(syst). © 1996 The American Physical Society.

Abstract:

We report on a search for the flavor-changing neutral current decays B⁰ d, s→μ⁺μ⁻, B⁺→μ⁺μ⁻K⁺, and B⁰→μ⁺μ⁻K^*0 using data from pp^- collisions at s = 1.8 TeV, collected with the Collider Detector at Fermilab during the 1992-1993 running period. We find no indication of such decays, and we set the following 90% confidence level upper limits on branching ratios: B\(B⁰→μ⁺μ⁻\)<1.6×10⁻⁶, B(B⁰ s→μ⁺μ⁻\)<8.4×10⁻⁶, B\(B⁺→μ⁺μ⁻K⁺\)<1.0×10⁻⁵, and B\(B⁰→μ⁺μ⁻K^*0\)<2.5×10⁻⁵. © 1996 The American Physical Society.

Abstract:

We present results from a search for anomalous WW and WZ production in pp^¯ collisions at √s = 1.8 TeV. We used pp^¯ → evjjX events observed during the 1992-1993 run of the Fermilab Tevatron collider, corresponding to an integrated luminosity of 13.7 ± 0.7pb⁻¹. A fit to the transverse momentum spectrum of the W boson yields direct limits on the CP-conserving anomalous WWγ and WWZ coupling parameters of −0.9 < Δk < 1.1 (with λ = 0) and −0.6 < λ < 0.7 (with Δk = 0) at the 95% confidence level, for a form factor scale Λ = 1.5 TeV, assuming that the WWγ and WWZ coupling parameters are equal. © 1996 The American Physical Society.

Abstract:

We present the result of a search for charged Higgs boson decays of the top quark, produced in p-p collisions at √s=1.8 TeV. When the charged Higgs boson is heavy and decays to a τ lepton, which subsequently decays hadronically, the resulting events have a unique signature: large missing transverse energy and the low-charged-multiplicity τ. Data collected in 1992 and 1993 at the Collider Detector at Fermilab, corresponding to 18.7±0.7 pb^-1, exclude new regions of combined top quark and charged Higgs boson mass, in extensions to the standard model with two Higgs doublets. © 1996 The American Physical Society.

Abstract:

We have searched for chargino-neutralino production (χ^± 1χ⁰ 2) in 1.8 TeV pp collisions, followed by their leptonic decays χ^± 1 → χ⁰ 1ℓ^±ν and χ⁰ 2→χ⁰ 1ℓ⁺ℓ^-. These trilepton events are expected within a framework of the minimal supersymmetric standard model (MSSM). In a 19.1pb^-1 data sample collected with a Collider Detector at Fermilab, no trilepton events were observed. Upper limits on σ(pp → χ^± 1χ⁰ 2)BR(χ^± 1→⁰ 2→3ℓ + X) were obtained for various MSSM parameter space regions, yielding new 95% confidence level lower limits for the neutralino (χ⁰ 2) mass which extend as high as 49GeV/c². © 1996 The American Physical Society.