Search for the Higgs boson using neural networks in events with missing energy and b-quark jets in pp collisions at square root(s) = 1.96 TeV.
Phys Rev Lett 104:14 (2010) 141801
Abstract:
We report on a search for the standard model Higgs boson produced in association with a W or Z boson in pp collisions at square root(s)=1.96 TeV recorded by the CDF II experiment at the Tevatron in a data sample corresponding to an integrated luminosity of 2.1 fb(-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 110 GeV/c(2) to 150 GeV/c(2). For a mass of 115 GeV/c(2) the observed (expected) limit is 6.9 (5.6) times the standard model prediction.First measurement of the b-Jet cross section in events with a W boson in pp̄ collisions at √s=1.96TeV
Physical Review Letters 104:13 (2010)
Abstract:
The cross section for jets from b quarks produced with a W boson has been measured in pp̄ collision data from 1.9fb-1 of integrated luminosity recorded by the CDF II detector at the Tevatron. The W+b-jets process poses a significant background in measurements of top quark production and prominent searches for the Higgs boson. We measure a b-jet cross section of 2.74±0.27(stat)±0.42(syst)pb in association with a single flavor of leptonic W boson decay over a limited kinematic phase space. This measured result cannot be accommodated in several available theoretical predictions. © 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
Abstract:
We present a search for the technicolor particles rho{T} and pi_{T} in the process pp-->rho{T}-->Wpi{T} at a center of mass energy of sqrt[s]=1.96 TeV. The search uses a data sample corresponding to approximately 1.9 fb{-1} of integrated luminosity accumulated by the CDF II detector at the Fermilab Tevatron. The event signature we consider is W-->lnu and pi{T}-->bb, bc or bu depending on the pi{T} charge. We select events with a single high-p{T} electron or muon, large missing transverse energy, and two jets. Jets corresponding to bottom quarks are identified with multiple b-tagging algorithms. The observed number of events and the invariant mass distributions are consistent with the standard model background expectations, and we exclude a region at 95% confidence level in the rho{T}-pi{T} mass plane. As a result, a large fraction of the region m(rho{T})=180-250 GeV/c{2} and m(pi{T})=95-145 GeV/c{2} is excluded.Studying the Underlying Event in Drell-Yan and High Transverse Momentum Jet Production at the Tevatron
(2010)