4 research outputs found

    Measurement of the top quark mass at CDF using the "neutrino ϕ\phi weighting" template method on a lepton plus isolated track sample

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    Submitted to Phys. Rev. DWe present a measurement of the top quark mass with t-tbar dilepton events produced in p-pbar collisions at the Fermilab Tevatron (s\sqrt{s}=1.96 TeV) and collected by the CDF II detector. A sample of 328 events with a charged electron or muon and an isolated track, corresponding to an integrated luminosity of 2.9 fb1^{-1}, are selected as t-tbar candidates. To account for the unconstrained event kinematics, we scan over the phase space for the azimuthal angles (ϕν1,ϕν2\phi_{\nu_1},\phi_{\nu_2}) of neutrinos and reconstruct the top quark mass by minimizing a χ2\chi^2 function in the t-tbar dilepton hypothesis. We assign χ2\chi^2-dependent weights to the solutions in order to build a preferred mass for each event. Preferred mass distributions (templates) are built from simulated t-tbar and background events, and parameterized in order to provide continuous probability density functions. A likelihood fit of the preferred mass distribution in data to a weighted sum of signal and background probability density functions gives a top quark mass of 165.53.3+3.4165.5^{+{3.4}}_{-{3.3}}(stat.)±3.1\pm 3.1(syst.) GeV/c2c^2

    Search for the Decays B(s)0e+μ{B^0_{(s)}\to e^+\mu^-} and B(s)0e+e{B^0_{(s)}\to e^+e^-} in CDF Run II

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    submitted to PRLWe report results from a search for the lepton flavor violating decays B(s)0e+μB^0_{(s)}\to e^+\mu^-, and the flavor-changing neutral-current decays B(s)0e+eB^0_{(s)} \to e^+ e^-. The analysis uses data corresponding to 2fb1{\rm 2 fb^{-1}} of integrated luminosity of ppˉp \bar{p} collisions at s=1.96TeV\sqrt{s}=1.96 {\rm TeV} collected with the upgraded Collider Detector (CDF II) at the Fermilab Tevatron. The observed number of B(s)0B^0_{(s)} candidates is consistent with background expectations. The resulting Bayesian upper limits on the branching ratios at 90% credibility level are B(Bs0e+μ)47.8TeV/c2\mathcal{B}(B^0_s \to e^{+}\mu^{-}) 47.8 {\rm TeV/c^2}, and MLQ(B0e+μ)>59.3TeV/c2{M_{LQ}}(B^0\to e^+ \mu^-) > 59.3 {\rm TeV/c^2}, at 90% credibility level

    Direct Measurement of the WW Production Charge Asymmetry in \ppbar Collisions at s=1.96\sqrt{s} = 1.96 TeV

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    submitted to Phys. Rev. LettWe present the first direct measurement of the WW production charge asymmetry as a function of the WW boson rapidity \yW in \ppbar collisions at s=1.96\sqrt{s} = 1.96 \TeV. We use a sample of \wenu events in data from 1 \ifb of integrated luminosity collected using the CDF II detector. In the region |\yW| < 3.0, this measurement is capable of constraining the ratio of up and down quark momentum distributions in the proton more directly than in previous measurements of the asymmetry that are a function of the charged-lepton pseudorapidity
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