Measurement of the W+ W- production cross section and search for anomalous WWγ and WWZ couplings in pp collisions at square root(s)=1.96 TeV.
Phys Rev Lett 104:20 (2010) 201801
Abstract:
This Letter describes the current most precise measurement of the W boson pair production cross section and most sensitive test of anomalous WWγ and WWZ couplings in pp collisions at a center-of-mass energy of 1.96 TeV. The WW candidates are reconstructed from decays containing two charged leptons and two neutrinos. Using data collected by the CDF II detector from 3.6 fb(-1) of integrated luminosity, a total of 654 candidate events are observed with an expected background of 320±47 events. The measured cross section is σ(pp→W+ W- +X)=12.1±0.9(stat)-1.4+1.6(syst) pb, which is in good agreement with the standard model prediction. The same data sample is used to place constraints on anomalous WWγ and WWZ couplings.Search for single top quark production in pp̄ collisions at √s=1.96TeV in the missing transverse energy plus jets topology
Physical Review D - Particles, Fields, Gravitation and Cosmology 81:7 (2010)
Abstract:
We report a search for single top quark production with the CDF II detector using 2.1fb-1 of integrated luminosity of pp̄ collisions at √s=1.96TeV. The data selected consist of events characterized by large energy imbalance in the transverse plane and hadronic jets, and no identified electrons and muons, so the sample is enriched in W→τν decays. In order to suppress backgrounds, additional kinematic and topological requirements are imposed through a neural network, and at least one of the jets must be identified as a b quark jet. We measure an excess of signal-like events in agreement with the standard model prediction, but inconsistent with a model without single top quark production by 2.1 standard deviations (σ), with a median expected sensitivity of 1.4σ. Assuming a top quark mass of 175GeV/c2 and ascribing the excess to single top quark production, the cross section is measured to be 4.9-2.2+2.5(stat+syst)pb, consistent with measurements performed in independent data sets and with the standard model prediction. © 2010 The American Physical Society.Search for the Higgs Boson Using Neural Networks in Events with Missing Energy and b-Quark Jets in pp̄ Collisions at √s=1.96TeV
Physical Review Letters 104:14 (2010)
Abstract:
We report on a search for the standard model Higgs boson produced in association with a W or Z boson in pp̄ collisions at √s=1.96TeV recorded by the CDF II experiment at the Tevatron in a data sample corresponding to an integrated luminosity of 2.1fb-1. We consider events which have no identified charged leptons, an imbalance in transverse momentum, and two or three jets where at least one jet is consistent with originating from the decay of a b hadron. We find good agreement between data and background predictions. We place 95% confidence level upper limits on the production cross section for several Higgs boson masses ranging from 110GeV/c2 to 150GeV/c2. For a mass of 115GeV/c2 the observed (expected) limit is 6.9 (5.6) times the standard model prediction. © 2010 The American Physical Society.Measurement of the top quark mass and pp̄→tt̄ cross section in the all-hadronic mode with the CDF II detector
Physical Review D - Particles, Fields, Gravitation and Cosmology 81:5 (2010)
Abstract:
We present a measurement of the top quark mass and of the top-antitop (tt̄) pair production cross section using pp̄ data collected with the CDF II detector at the Tevatron Collider at the Fermi National Accelerator Laboratory and corresponding to an integrated luminosity of 2.9fb-1. We select events with six or more jets satisfying a number of kinematical requirements imposed by means of a neural-network algorithm. At least one of these jets must originate from a b quark, as identified by the reconstruction of a secondary vertex inside the jet. The mass measurement is based on a likelihood fit incorporating reconstructed mass distributions representative of signal and background, where the absolute jet energy scale (JES) is measured simultaneously with the top quark mass. The measurement yields a value of 174.8±2.4(stat+JES)-1.0+1.2(syst)GeV/c2, where the uncertainty from the absolute jet energy scale is evaluated together with the statistical uncertainty. The procedure also measures the amount of signal from which we derive a cross section, σtt̄=7.2±0.5(stat)±1.0(syst) ±0.4(lum)pb, for the measured values of top quark mass and JES. © 2010 The American Physical Society.Search for technicolor particles produced in association with a W Boson at CDF.
Phys Rev Lett 104:11 (2010) 111802