We search for the standard model Higgs boson produced in association with an electroweak vector boson in events with no identified charged leptons, large imbalance in transverse momentum, and two jets where at least one contains a secondary vertex consistent with the decay of b hadrons. We use ≈1 fb−1 integrated luminosity of p{bar p} collisions at √s = 1.96 TeV recorded by the CDF II experiment at the Tevatron. We find 268 (16) single (double) b-tagged candidate events, where 248 ± 43 (14.4 ± 2.7) are expected from standard model background processes. We place 95% confidence level upper limits on the Higgs boson production cross section for several Higgs boson masses ranging from 110 GeV/c2 to 140 GeV/c2. For a mass of 115 GeV/c2 the observed (expected) limit is 20.4 (14.2) times the standard model prediction.

We search for the standard model Higgs boson produced in association with an electroweak vector boson in events with no identified charged leptons, large imbalance in transverse momentum, and two jets where at least one contains a secondary vertex consistent with the decay of b hadrons. We use ≈1 fb−1 integrated luminosity of p{bar p} collisions at √s = 1.96 TeV recorded by the CDF II experiment at the Tevatron. We find 268 (16) single (double) b-tagged candidate events, where 248 ± 43 (14.4 ± 2.7) are expected from standard model background processes. We place 95% confidence level upper limits on the Higgs boson production cross section for several Higgs boson masses ranging from 110 GeV/c2 to 140 GeV/c2. For a mass of 115 GeV/c2 the observed (expected) limit is 20.4 (14.2) times the standard model prediction.

We report on a search for the standard model Higgs boson produced in association with a W or Z boson in p{bar p} 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 predictions. We place 95% confidence level upper limits on the production cross section for several Higgs boson masses ranging from 110 GeV/c2 to 150 GeV/c2. For a mass of 115 GeV/c2 the observed (expected) limit is 6.9 (5.6) times the standard model prediction.

A search for the Standard Model Higgs boson was carried out in WH 2!l[nu]b{bar b} process in p{bar p} collisions at a center of mass energy of 1.96 TeV, where W, H, l, [nu], b and p denote either a W or W− boson, Higgs boson, lepton (electron or muon), neutrino, bottom quark and proton, respectively. The data were collected with the Collider Detector at Fermilab from February 2002 to August 2004. The corresponding integrated luminosity is 319 pb−1. We select events containing a single high-p{sub T} electron or muon, a large imbalance of the total transverse energy from a neutrino and two b quark jets. The main backgrounds are the W + light flavor/gluon jets and W + heavy flavor jets processes. Requiring the secondary vertex b-tagging enables us to reject the W + light flavor/gluon jets events effectively. After all event selections, they observe 187 events which is in agreement with the Standard Model background expectation of 175.2 ± 26.3 events, and there is no significant excess originating from the Higgs boson in the reconstructed dijet invariant mass distribution. They thus set a 95% confidence level upper limit on the production cross section times branching ratio decaying into bb, [sigma](p{bar p} 2!W H) x Br(H 2!b{bar b}). The detection efficiency for the W H events, which is necessary for calculating the upper limit, is determined by the Monte Carlo except for the lepton identification efficiency, the lepton trigger efficiency and the b-tagging efficiency which are estimated from the CDF real data. The resultant 95% confidence level upper limits are 10.0 pb to 2.8 pb using at least one b-tagging method and 9.7 pb to 6.6 pb using double b-tagging method for the Higgs boson mass region 110 GeV/c2 to 150 GeV/c2, where the Standard Model prediction is approximately one or two order of magnitude lower than the results.

A search for the standard model Higgs boson is performed in 6.4 fb−1 of p{bar p} collisions at √s = 1.96 TeV, collected with the D0 detector during Run II of the Fermilab Tevatron. The final state considered is a pair of jets originating from b quarks and missing transverse energy, as expected from p{bar p} → ZH → [nu]{bar [nu]}b{bar b} production. The search is also sensitive to the WH → l{nu}b{bar b} channel, where the charged lepton is not identified. Boosted decision trees are used to discriminate signal from background. Good agreement is observed between data and expected backgrounds, and a limit is set at 95% C.L. on the section multiplied by branching fraction of (p{bar p} → (Z/W)H) x (H → b{bar b}). For a Higgs boson mass of 115 GeV, the observed limit is a factor of 3.5 larger than the value expected from the standard model.