We provide the most precise measurement of the WW production cross section in pp collisions to date at a center of mass energy of 1.96 TeV, and set limits on the associated trilinear gauge couplings. ...The WW -> l nu l(')nu (l, l(')=e, mu) decay channels are analyzed in 1 fb(-1) of data collected by the D0 detector at the Fermilab Tevatron Collider. The measured cross section is sigma(pp -> WW)=11.5 +/- 2.1(stat+syst)+/- 0.7(lumi) pb. One- and two-dimensional 95% C.L. limits on trilinear gauge couplings are provided.
We present a measurement of the top quark pair production cross section in p (p) over bar collisions at root s = 1.96 TeV using approximately 1 fb(-1) collected with the DO detector. We consider ...decay channels containing two high p(T) charged leptons where one lepton is identified as an electron or a muon while the other lepton can be an electron, a muon or a hadronically decaying tau lepton. For a mass of the top quark of 170 GeV, the measured cross section is 7.5(-1.0)(+1.0)(stat)(-0.6)(+0.7)(syst)(-0.5)(+0.6)(lumi) pb. Using l tau events only, we measure: sigma(t (t) over bar) x B(t (t) over bar -> l tau b (b) over bar) = 0.13(-0.08)(+0.09)(stat)(-0.06)(+0.06)(syst)(-0.02)(+0.02)(lumi) pb. Comparing the measured cross section as a function of the mass of the top quark with a partial next-to-next-to leading order Quantum Chroniodynamics theoretical prediction, we extract a mass of the top quark of 171.5(-8.8)(+9-9) GeV, in agreement with direct measurements.
We have searched for third generation leptoquarks (LQ(3)) using 1.05 fb(-1) of data collected with the D0 detector at the Fermilab Tevatron Collider operating at s=1.96 TeV. We set a 95% C.L. lower ...limit of 210 GeV on the mass of a scalar LQ(3) state decaying solely to a b quark and a tau lepton.
Single top quarks at the Fermilab Tevatron Heinson, A. P.; Belyaev, A. S.; Boos, E. E.
Physical review. D, Particles and fields,
09/1997, Letnik:
56, Številka:
5
Journal Article
We present a search for the standard model Higgs boson using hadronically decaying tau leptons, in 1 fb(-1) of data collected with the D0 detector at the Fermilab Tevatron pp collider. We select two ...final states: tau+/- plus missing transverse energy and b jets, and tau+ tau- plus jets. These final states are sensitive to a combination of associated W/Z boson plus Higgs boson, vector boson fusion, and gluon-gluon fusion production processes. The observed ratio of the combined limit on the Higgs production cross section at the 95% C.L. to the standard model expectation is 29 for a Higgs boson mass of 115 GeV.
AIP Conf.Proc.870:223-227,2006 First observed in 1995, the top quark is one of a pair of third-generation
quarks in the Standard Model of particle physics. It has charge +2/3e and a
mass of 171.4 ...GeV, about 40 times heavier than its partner, the bottom quark.
The CDF and D0 collaborations have identified several hundred events containing
the decays of top-antitop pairs in the large dataset collected at the Tevatron
proton-antiproton collider over the last four years. They have used these
events to measure the top quark's mass to nearly 1% precision and to study
other top quark properties. The mass of the top quark is a fundamental
parameter of the Standard Model, and knowledge of its value with small
uncertainty allows us to predict properties of the as-yet-unobserved Higgs
boson. This paper presents the status of the measurements of the top quark
mass.
At the Tevatron Collider at Fermilab, a large number of top quarks have been
produced in the ongoing run. The CDF and DZero collaborations have made first
measurements of the ttbar cross section in ...several decay channels, and have
measured the top quark mass. In addition, they have set new limits on the cross
sections for single top quark production, and have started to measure some of
the properties of the top quark via studies of its decays. This paper
summarizes the status of these measurements and discusses where they are
heading in the next few years. The paper is based on a talk I gave at the
Rencontres du Vietnam in Hanoi, August 2004; the results have been updated to
show the latest values and new measurements.
We present a new method for modeling the hadronic recoil in
W
→
ℓ
ν
events produced at hadron colliders. The recoil is chosen from a library of recoils in
Z
→
ℓ
ℓ
data events and overlaid on a ...simulated
W
→
ℓ
ν
event. Implementation of this method requires that the data recoil library describe the properties of the measured recoil as a function of the true, rather than the measured, transverse momentum of the boson. We address this issue using a multidimensional Bayesian unfolding technique. We estimate the statistical and systematic uncertainties from this method for the W boson mass and width measurements assuming
1
fb
-
1
of data from the Fermilab Tevatron. The uncertainties are found to be small and comparable to those of a more traditional parameterized recoil model. For the high precision measurements that will be possible with data from Run II of the Fermilab Tevatron and from the CERN LHC, the method presented in this paper may be advantageous, since it does not require an understanding of the measured recoil from first principles.
We present the first observation of the Z gamma -> nu(nu) over bar gamma process at the Fermilab Tevatron at 5.1 standard deviations significance, based on 3.6 fb(-1) of integrated luminosity ...collected with the D0 detector at the Fermilab Tevatron p (p) over bar Collider at root s = 1.96 TeV. The measured Z gamma production cross section multiplied by the branching fraction of Z -> nu(nu) over bar is 32 +/- 9(stat + syst) +/- 2(lumi) fb for the photon E(T) > 90 GeV. It is in agreement with the standard model prediction of 39 +/- 4 fb. We set limits on anomalous trilinear Z gamma gamma and ZZ gamma gauge boson couplings, most of which are the most restrictive to date.
PDF
