Jeff Tseng

Abstract:

We report a measurement of the ratios of the decay rates of the B+, B0, and B0s mesons into exclusive final states containing a J/Ψ meson. The final states were selected from 19.6 pb-1 of pp collisions recorded by the Collider Detector at Fermilab. These data are interpreted to determine the b quark fragmentation fractions fu, fd, and fs. We also determine the branching fractions for the decay modes (formula presented). We discuss the implications of these measurements to B meson decay models. © 1996 The American Physical Society.

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 B0d, 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(B0s→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 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.