Measurement of the fraction of t-tbar production via gluon-gluon fusion in p-pbar collisions at sqrt(s)=1.96 TeV
ArXiv 0807.4262 (2008)
Search for the Higgs boson produced with $Z \to \ell^+\ell^-$ in $p\bar{p}$ collisions at $\sqrt{s}=$ 1.96 TeV
ArXiv 0807.4493 (2008)
Search for large extra dimensions in final states containing one photon or jet and large missing transverse energy produced in p-pbar collisions at sqrt(s) = 1.96 TeV
ArXiv 0807.3132 (2008)
Evidence for production of single top quarks
Physical Review D - Particles, Fields, Gravitation and Cosmology 78:1 (2008)
Abstract:
We present first evidence for the production of single top quarks in the D0 detector at the Fermilab Tevatron pp̄ collider. The standard model predicts that the electroweak interaction can produce a top quark together with an antibottom quark or light quark, without the antiparticle top-quark partner that is always produced from strong-coupling processes. Top quarks were first observed in pair production in 1995, and since then, single top-quark production has been searched for in ever larger data sets. In this analysis, we select events from a 0.9fb-1 data set that have an electron or muon and missing transverse energy from the decay of a W boson from the top-quark decay, and two, three, or four jets, with one or two of the jets identified as originating from a b hadron decay. The selected events are mostly backgrounds such as W+jets and tt̄ events, which we separate from the expected signals using three multivariate analysis techniques: boosted decision trees, Bayesian neural networks, and matrix-element calculations. A binned likelihood fit of the signal cross section plus background to the data from the combination of the results from the three analysis methods gives a cross section for single top-quark production of σ(pp̄→tb+X,tqb+X)=4.7±1.3pb. The probability to measure a cross section at this value or higher in the absence of signal is 0.014%, corresponding to a 3.6 standard deviation significance. The measured cross section value is compatible at the 10% level with the standard model prediction for electroweak top-quark production. We use the cross section measurement to directly determine the Cabibbo-Kobayashi-Maskawa quark mixing matrix element that describes the Wtb coupling and find |Vtbf1L|=1.31-0.21+0.25, where f1L is a generic vector coupling. This model-independent measurement translates into 0.68<|Vtb|≤1 at the 95% C.L. in the standard model. © 2008 The American Physical Society.Measurement of the Inclusive Jet Cross Section at the Fermilab Tevatron p-pbar Collider Using a Cone-Based Jet Algorithm
ArXiv 0807.2204 (2008)