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;{-1} of data recorded with the D0 detector at Fermilab. The a bosons are required to either both decay to micro;{+}micro;{-} or one to micro;{+}micro;{-} and the other to tau;{+}tau;{-}. No significant signal is observed, and we set limits on its production as functions of M_{a} and M_{h}.
Measurements of semileptonic K L decay form factors Alexopoulos, T.; Arenton, M.; Barbosa, R. F. ...
Physical review. D, Particles, fields, gravitation, and cosmology,
11/2004, Letnik:
70, Številka:
9
Journal Article
We present the first observation of the Zgamma --> nunuover 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 ppover Collider at sqrts = 1.96 TeV. The measured Zgamma production cross section multiplied by the branching fraction of Z --> nunuover 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 Zgammagamma and ZZgamma gauge boson couplings, most of which are the most restrictive to date.
First measurements of the differential cross sections d;{3}sigma/(dp_{T};{gamma}dy;{gamma}dy;{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_{T};{gamma}<150 GeV, photon rapidities |y;{gamma}|<1.0, jet rapidities |y;{jet}|<0.8, and jet transverse momenta p_{T};{jet}>15 GeV. The results are based on an integrated luminosity of 1 fb;{-1} in ppover collisions at sqrts=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-1 of integrated luminosity collected with the D0 detector at the ...Fermilab Tevatron in pp collisions at square root 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 <5.4 x 10-6, which corresponds to a significance of 4.4 standard deviations.
We search for the semi-inclusive process Bs0-->Ds(*)Ds(*) using 2.8 fb(-1) of pp collisions at sqrts=1.96 TeV recorded by the D0 detector operating at the Fermilab Tevatron Collider. We observe ...26.6+/-8.4 signal events with a significance above background of 3.2 standard deviations yielding a branching ratio of B(Bs0-->Ds(*)Ds(*))=0.035+/-0.010(stat.)+/-0.011(syst.). Under certain theoretical assumptions, these double-charm final states saturate CP-even eigenstates in the Bs0 decays resulting in a width difference of DeltaGammasCP/Gammas=0.072+/-0.021(stat.)+/-0.022(syst.).
We present results of a search for WH-->lnubbover production in ppover collisions based on the analysis of 1.05 fb;{-1} of data collected by the D0 experiment at the Fermilab Tevatron, using a ...neural network for separating the signal from backgrounds. No signal-like excess is observed, and we set 95% C.L. upper limits on the WH production cross section multiplied by the branching ratio for H-->bbover for Higgs boson masses between 100 and 150 GeV. For a mass of 115 GeV, we obtain an observed (expected) limit of 1.5 (1.4) pb, a factor of 11.4 (10.7) times larger than the standard model prediction.
The first search in ppover collisions at sqrts=1.96 TeV for the production of neutral Higgs bosons in association with bottom quarks and decaying in two tau leptons is presented. The cross section ...for this process is enhanced in many extensions of the standard model, such as its minimal supersymmetric extension (MSSM) at large tanbeta. The data, corresponding to an integrated luminosity of 328 pb;{-1}, were collected with the D0 detector at the Fermilab Tevatron Collider. An upper limit is set on the production cross section of neutral Higgs bosons in the mass range of 90 to 150 GeV, and this limit is used to exclude part of the MSSM parameter space.
In a data sample of approximately 1.3 fb;{-1} collected with the D0 detector between 2002 and 2006, the orbitally excited charm state D_{s1};{+/-}(2536) has been observed with a measured mass of ...2535.7+/-0.6(stat)+/-0.5(syst) MeV/c;{2} via the decay mode B_{s};{0}-->D_{s1};{-}(2536)mu;{+}nu_{mu}X. A first measurement is made of the branching ratio product Br(bover -->D_{s1};{-}(2536)mu;{+}nu_{mu}X)xBr(D_{s1};{-}-->D;{*-}K_{S};{0}). Assuming that D_{s1};{-}(2536) production in semileptonic decay is entirely from B_{s};{0}, an extraction of the semileptonic branching ratio Br(B_{s};{0}-->D_{s1};{-}(2536)mu;{+}nu_{mu}X) is made.
We report on a search for large extra spatial dimensions in the dielectron and diphoton channels using a data sample of 1.05 fb;{-1} of ppover collisions at a center-of-mass energy of 1.96 TeV ...collected by the D0 detector at the Fermilab Tevatron Collider. The invariant mass spectrum of the data agrees well with the prediction of the standard model. We find the most restrictive 95% C.L. lower limits on the effective Planck scale between 2.1 and 1.3 TeV for 2 to 7 extra dimensions.
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