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Register a new userMeasurement of the $WZ$ Cross Section and Triple Gauge Couplings in $p bar p$ Collisions at $sqrt{s} = 1.96$ TeV
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This Letter describes the current most precise measurement of the $WZ$ production cross section as well as limits on anomalous $WWZ$ couplings at a center-of-mass energy of 1.96 TeV in proton-antiproton collisions for the Collider Detector at Fermilab (CDF). $WZ$ candidates are reconstructed from decays containing three charged leptons and missing energy from a neutrino, where the charged leptons are either electrons or muons. Using data collected by the CDF II detector (7.1 fb$^{-1}$ of integrated luminosity), 63 candidate events are observed with the expected background contributing $8 pm 1$ events. The measured total cross section $sigma (p bar p to WZ) = 3.93_{-0.53}^{+0.60}(text{stat})_{-0.46}^{+0.59}(text{syst}) $ pb is in good agreement with the standard model prediction of $3.50pm 0.21$. The same sample is used to set limits on anomalous $WWZ$ couplings.
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We present a measurement of the inclusive jet cross section using the Run II cone algorithm and data collected by the D0 experiment in p pbar collisions at a center-of-mass energy sqrt(s)=1.96 TeV, corresponding to an integrated luminosity of 0.70 fb^(-1). The jet energy calibration and the method used to extract the inclusive jet cross section are described. We discuss the main uncertainties, which are dominated by the jet energy scale uncertainty. The results cover jet transverse momenta from 50 GeV to 600 GeV with jet rapidities in the range -2.4 to 2.4 and are compared to predictions using recent proton parton distribution functions. Studies of correlations between systematic uncertainties in transverse momentum and rapidity are presented.
We describe a measurement of the ratio of the cross sections times branching fractions of the $B_c^+$ meson in the decay mode $B_c^+ rightarrow J/psi mu u$ to the $B^+$ meson in the decay mode $B^+ rightarrow J/psi K^+$ in proton-antiproton collisions at center-of-mass energy $sqrt{s}=1.96$ TeV. The measurement is based on the complete CDF Run II data set, which comes from an integrated luminosity of $8.7,{rm fb}^{-1}$. The ratio of the production cross sections times branching fractions for $B_c^+$ and $B_c^+$ mesons with momentum transverse to the beam greater than $6~textrm{GeV}/c$ and rapidity magnitude smaller than 0.6 is $0.211pm 0.012~mbox{(stat)}^{+0.021}_{-0.020}~mbox{(syst)}$. Using the known $B^+ rightarrow J/psi K^+$ branching fraction, the known $B^+$ production cross section, and a selection of the predicted $B_c^+ rightarrow J/psi mu u$ branching fractions, the range for the total $B_c^+$ production cross section is estimated.
We report on a measurement of the $D^{+}$-meson production cross section as a function of transverse momentum ($p_T$) in proton-antiproton ($pbar{p}$) collisions at 1.96 TeV center-of-mass energy, using the full data set collected by the Collider Detector at Fermilab in Tevatron Run II and corresponding to 10 fb$^{-1}$ of integrated luminosity. We use $D^{+} to K^-pi^+pi^+$ decays fully reconstructed in the central rapidity region $|y|<1$ with transverse momentum down to 1.5 GeV/$c$, a range previously unexplored in $pbar{p}$ collisions. Inelastic $pbar{p}$-scattering events are selected online using minimally-biasing requirements followed by an optimized offline selection. The $K^-pi^+pi^+$ mass distribution is used to identify the $D^+$ signal, and the $D^+$ transverse impact-parameter distribution is used to separate prompt production, occurring directly in the hard scattering process, from secondary production from $b$-hadron decays. We obtain a prompt $D^+$ signal of 2950 candidates corresponding to a total cross section $sigma(D^+, 1.5 < p_T < 14.5~mbox{GeV/}c, |y|<1) = 71.9 pm 6.8 (mbox{stat}) pm 9.3 (mbox{syst})~mu$b. While the measured cross sections are consistent with theoretical estimates in each $p_T$ bin, the shape of the observed $p_T$ spectrum is softer than the expectation from quantum chromodynamics. The results are unique in $pbar{p}$ collisions and can improve the shape and uncertainties of future predictions.
We present a measurement of the elastic differential cross section $dsigma(pbar{p}rightarrow pbar{p})/dt$ as a function of the four-momentum-transfer squared t. The data sample corresponds to an integrated luminosity of $approx 31 nb^{-1}$ collected with the D0 detector using dedicated Tevatron $pbar{p} $ Collider operating conditions at sqrt(s) = 1.96 TeV and covers the range $0.26 <|t|< 1.2 GeV^2$. For $|t|<0.6 GeV^2$, dsigma/dt is described by an exponential function of the form $Ae^{-b|t|}$ with a slope parameter $ b = 16.86 pm 0.10(stat) pm 0.20(syst) GeV^{-2}$. A change in slope is observed at $|t| approx 0.6 GeV^2$, followed by a more gradual |t| dependence with increasing values of |t|.
A measurement of vector boson ($V$) production in conjunction with a $D^{*}(2010)^+$ meson is presented. Using a data sample corresponding to $9.7, {rm fb}^{-1}$ of ^Mproton-antiproton collisions at center-of-mass energy $sqrt{s}=1.96rm~ TeV$ produced by the Fermilab Tevatron, we reconstruct $V+D^{*+}$ samples with the CDF~II detector. The $D^{*+}$ is fully reconstructed in the $D^{*}(2010)^+ rightarrow D^{0}(to K^-pi^+)pi^+$ decay mode. This technique is sensitive to the associated production of vector boson plus charm or bottom mesons. We measure the ratio of production cross sections $sigma(W+D^{*})/sigma(W)$ = $[1.75pm 0.13 {rm (stat)}pm 0.09 {rm (syst)}]% $ and $sigma(Z+D^{*})/sigma(Z)$ = $[1.5pm 0.4 {rm (stat)} pm 0.2 {rm (syst)}]% $ and perform a differential measurement of $dsigma(W+D^{*})/dp_T(D^{*})$. Event properties are utilized to determine the fraction of $V+D^{*}(2010)^+$ events originating from different production processes. The results are in agreement with the predictions obtained with the {sc pythia} program, limiting possible contribution from non-standard-model physics processes.
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