Exclusion of exotic top-like quarks with -4/3 electric charge using jet-charge tagging in single-lepton ttbar events at CDF
(2013)
Exclusion of exotic top-like quarks with -4/3 electric charge using jet-charge tagging in single-lepton ttbar events at CDF
ArXiv 1304.4141 (2013)
Abstract:
We report on a measurement of the top-quark electric charge in ttbar events in which one W boson originating from the top-quark pair decays into leptons and the other into hadrons. The event sample was collected by the CDF II detector in sqrt(s)=1.96 TeV proton-antiproton collisions and corresponds to 5.6 fb^(-1). We find the data to be consistent with the standard model and exclude the existence of an exotic quark with -4/3 electric charge and mass of the conventional top quark at the 99% confidence level.Search for Bs0→μ+μ- and B0→μ+μ- decays with the full CDF Run II data set
Physical Review D - Particles, Fields, Gravitation and Cosmology 87:7 (2013)
Abstract:
We report on a search for Bs0→μ+μ- and B0→μ+μ- decays using proton-antiproton collision data at √s=1.96 TeV corresponding to 10 fb-1 of integrated luminosity collected by the CDF II detector at the Fermilab Tevatron collider. The observed number of B0 candidates is consistent with background-only expectations and yields an upper limit on the branching fraction of B(B0→μ+μ-)<4.6×10-9 at 95% confidence level. We observe an excess of Bs0 candidates. The probability that the background processes alone could produce such an excess or larger is 0.94%. The probability that the combination of background and the expected standard model rate of Bs0→μ+μ- could produce such an excess or larger is 6.8%. These data are used to determine a branching fraction B(Bs0→μ+μ-)=(1.3-0.7+0.9) ×10-8 and provide an upper limit of B(Bs0→μ +μ-)<3.1×10-8 at 95% confidence level. © 2013 American Physical Society.Search for resonant top-antitop production in the lepton plus jets decay mode using the full CDF data set
Physical Review Letters 110:12 (2013)
Abstract:
This Letter reports a search for a narrow resonant state decaying into two W bosons and two b quarks where one W boson decays leptonically and the other decays into a quark-antiquark pair. The search is particularly sensitive to top-antitop resonant production. We use the full data sample of proton-antiproton collisions at a center-of-mass energy of 1.96 TeV collected by the CDF II detector at the Fermilab Tevatron, corresponding to an integrated luminosity of 9.45 fb-1. No evidence for resonant production is found, and upper limits on the production cross section times branching ratio for a narrow resonant state are extracted. Within a specific benchmark model, we exclude a Z′ boson with mass, MZ′, below 915 GeV/c2 decaying into a top-antitop pair at the 95% credibility level assuming a Z′ boson decay width of ΓZ′=0.012M Z′. This is the most sensitive search for a narrow qq̄-initiated tt̄ resonance in the mass region below 750 GeV/c2. © 2013 American Physical Society.Measurement of the mass difference between top and antitop quarks
Physical Review D - Particles, Fields, Gravitation and Cosmology 87:5 (2013)