Measurements of the top-quark mass and the tt̄ cross section in the hadronic τ+jets decay channel at √s=1.96TeV
Physical Review Letters 109:19 (2012)
Abstract:
We present the first direct measurement of the top-quark mass using tt̄ events decaying in the hadronic τ+jets decay channel. Using data corresponding to an integrated luminosity of 2.2fb-1 collected by the CDF II detector in pp̄ collisions at √s=1.96TeV at the Fermilab Tevatron, we measure the tt̄ cross section, σtt̄, and the top-quark mass, Mtop. We extract Mtop from a likelihood based on per-event probabilities calculated with leading-order signal and background matrix elements. We measure σtt̄=8. 8±3.3(stat)±2.2(syst)pb and Mtop=172.7±9.3(stat) ±3.7(syst)GeV/c2. © 2012 American Physical Society.Search for neutral Higgs bosons in events with multiple bottom quarks at the Tevatron
Physical Review D - Particles, Fields, Gravitation and Cosmology 86:9 (2012)
Abstract:
The combination of searches performed by the CDF and D0 collaborations at the Fermilab Tevatron Collider for neutral Higgs bosons produced in association with b quarks is reported. The data, corresponding to 2.6fb -1 of integrated luminosity at CDF and 5.2fb -1 at D0, have been collected in final states containing three or more b jets. Upper limits are set on the cross section multiplied by the branching ratio varying between 44 pb and 0.7 pb in the Higgs boson mass range 90 to 300 GeV, assuming production of a narrow scalar boson. Significant enhancements to the production of Higgs bosons can be found in theories beyond the standard model, for example, in supersymmetry. The results are interpreted as upper limits in the parameter space of the minimal supersymmetric standard model in a benchmark scenario favoring this decay mode. © 2012 American Physical Society.Measurement of the top quark forward-backward production asymmetry and its dependence on event kinematic properties
(2012)
Measurement of the top quark forward-backward production asymmetry and its dependence on event kinematic properties
ArXiv 1211.1003 (2012)
Abstract:
We present new measurements of the inclusive forward-backward ttbar production asymmetry, AFB, and its dependence on several properties of the ttbar system. The measurements are performed with the full Tevatron data set recorded with the CDF II detector during ppbar collisions at sqrt(s) = 1.96 TeV, corresponding to an integrated luminosity of 9.4 fb^(-1). We measure the asymmetry using the rapidity difference Delta-y=y_(t)-y_(tbar). Parton-level results are derived, yielding an inclusive asymmetry of 0.164+/-0.047 (stat + syst). We observe a linear dependence of AFB on the top-quark pair mass M(ttbar) and the rapidity difference |Delta-y| at detector and parton levels. Assuming the standard model, the probabilities to observe the measured values or larger for the detector-level dependencies are 7.4*10^(-3) and 2.2*10^(-3) for M(ttbar) and |Delta-y| respectively. Lastly, we study the dependence of the asymmetry on the transverse momentum of the ttbar system at the detector level. These results are consistent with previous lower-precision measurements and provide additional quantification of the functional dependencies of the asymmetry.Search for the standard model higgs boson produced in association with top quarks using the full CDF data set
Physical Review Letters 109:18 (2012)