We report results from a search for production of a neutral Higgs boson in association with a b quark. We search for Higgs decays to {tau} pairs with one {tau} subsequently decaying to a muon and the ...other to hadrons. The data correspond to 2.7 fb{sup -1} of pp collisions recorded by the D0 detector at {radical}(s)=1.96 TeV. The data are found to be consistent with background predictions. The result allows us to exclude a significant region of parameter space of the minimal supersymmetric model.
A search is performed for the standard model Higgs boson in 5.2 fb{sup -1} of pp collisions at sq root(s)=1.96 TeV, collected with the D0 detector at the Fermilab Tevatron Collider. The final state ...considered is a pair of b jets and large missing transverse energy, as expected from pp->ZH->nunubb production. The search is also sensitive to the WH->lnubb channel when the charged lepton is not identified. For a Higgs boson mass of 115 GeV, a limit is set at the 95% C.L. on the cross section multiplied by branching fraction for pp->(Z/W)H(H->bb) that is a factor of 3.7 larger than the standard model value, consistent with the factor of 4.6 expected.
A search for the standard model Higgs boson is presented using events with two charged leptons and large missing transverse energy selected from 5.4 fb{sup -1} of integrated luminosity in pp ...collisions at sq root(s)=1.96 TeV collected with the D0 detector at the Fermilab Tevatron collider. No significant excess of events above background predictions is found, and observed (expected) upper limits at 95% confidence level on the rate of Higgs boson production are derived that are a factor of 1.55 (1.36) above the predicted standard model cross section at m{sub H}=165 GeV.
We present the first measurement of dijet angular distributions in pp collisions at sq root(s)=1.96 TeV at the Fermilab Tevatron Collider. The measurement is based on a dataset corresponding to an ...integrated luminosity of 0.7 fb{sup -1} collected with the D0 detector. Dijet angular distributions have been measured over a range of dijet masses, from 0.25 TeV to above 1.1 TeV. The data are in good agreement with the predictions of perturbative QCD and are used to constrain new physics models including quark compositeness, large extra dimensions, and TeV{sup -1} scale extra dimensions. For all models considered, we set the most stringent direct limits to date.
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->lnul{sup '}nu (l, l{sup '}=e, mu) decay channels are analyzed in 1 fb{sup -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 report on a first search for resonant pair production of neutral long-lived particles (NLLP) which each decay to a bb pair, using 3.6 fb{sup -1} of data recorded with the D0 detector at the ...Fermilab Tevatron collider. We search for pairs of displaced vertices in the tracking detector at radii in the range 1.6-20 cm from the beam axis. No significant excess is observed above background, and upper limits are set on the production rate in a hidden-valley benchmark model for a range of Higgs boson masses and NLLP masses and lifetimes.
We report on a first search for production of the lightest neutral CP-even Higgs boson (h) in the next-to-minimal supersymmetric standard model, where h decays to a pair of neutral pseudoscalar Higgs ...bosons (a), using 4.2 fb{sup -1} of data recorded with the D0 detector at Fermilab. The a bosons are required to either both decay to {mu}{sup +}{mu}{sup -} or one to {mu}{sup +}{mu}{sup -} and the other to {tau}{sup +}{tau}{sup -}. No significant signal is observed, and we set limits on its production as functions of M{sub a} and M{sub h}.
We present the first observation of the Z{gamma}{yields}{nu}{nu}{gamma} process at the Fermilab Tevatron at 5.1 standard deviations significance, based on 3.6 fb{sup -1} of integrated luminosity ...collected with the D0 detector at the Fermilab Tevatron pp Collider at {radical}(s)=1.96 TeV. The measured Z{gamma} production cross section multiplied by the branching fraction of Z{yields}{nu}{nu} is 32{+-}9(stat+syst){+-}2(lumi) fb for the photon E{sub 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.
First measurements of the differential cross sections d{sup 3}{sigma}/(dp{sub T}{sup {gamma}}dy{sup {gamma}}dy{sup jet}) for the inclusive production of a photon in association with a heavy quark (b, ...c) jet are presented, covering photon transverse momenta 30<p{sub T}{sup {gamma}}<150 GeV, photon rapidities |y{sup {gamma}}|<1.0, jet rapidities |y{sup jet}|<0.8, and jet transverse momenta p{sub T}{sup jet}>15 GeV. The results are based on an integrated luminosity of 1 fb{sup -1} in pp collisions at {radical}(s)=1.96 TeV recorded with the D0 detector at the Fermilab Tevatron Collider. The results are compared with next-to-leading order perturbative QCD predictions.
We present first evidence for WW+WZ production in lepton+jets final states at a hadron collider. The data correspond to 1.07 fb{sup -1} of integrated luminosity collected with the D0 detector at the ...Fermilab Tevatron in pp collisions at {radical}(s)=1.96 TeV. The observed cross section for WW+WZ production is 20.2{+-}4.5 pb, consistent with the standard model and more precise than previous measurements in fully leptonic final states. The probability that background fluctuations alone produce this excess is <5.4x10{sup -6}, which corresponds to a significance of 4.4 standard deviations.
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