0000000000131662

AUTHOR

Benjamin Ko

showing 4 related works from this author

Search for Charged Higgs Bosons in Decays of Top Quarks inpp¯Collisions ats=1.96  TeV

2009

We report on the first direct search for charged Higgs bosons in decays of top quarks in p{bar p} collisions at {radical}s = 1.96 TeV. The search uses a data sample corresponding to an integrated luminosity of 2.2 fb{sup -1} collected by the CDF II detector at Fermilab, and looks for a resonance in the invariant mass distribution of two jets in the lepton+jets sample of t{bar t} candidates. We observe no evidence of charged Higgs bosons in top quark decays. Hence, 95% upper limits on the top quark decay branching ratio are placed at {Beta}(t {yields} H{sup +}b) < 0.1 to 0.3 for charged Higgs boson masses of 60 to 150 GeV/c{sup 2}, assuming {Beta}(H{sup +} {yields} c{bar s}) = 1.0. The upper…

QuarkPhysicsTop quarkParticle physics010308 nuclear & particles physicsBranching fractionHigh Energy Physics::PhenomenologyGeneral Physics and AstronomyElementary particle01 natural sciences7. Clean energyStandard ModelNuclear physics0103 physical sciencesHiggs bosonHigh Energy Physics::Experiment010306 general physicsLeptonBosonPhysical Review Letters
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Search forWWandWZResonances Decaying to Electron, MissingET, and Two Jets inpp¯Collisions ats=1.96  TeV.

2009

We present a search for WW and WZ production in final states that contain a charged lepton (electron or muon) and at least two jets, produced in {radical}(s)=1.96 TeV pp collisions at the Fermilab Tevatron, using data corresponding to 1.2 fb{sup -1} of integrated luminosity collected with the CDF II detector. Diboson production in this decay channel has yet to be observed at hadron colliders due to the large single W plus jets background. An artificial neural network has been developed to increase signal sensitivity, as compared with an event selection based on conventional cuts. We set a 95% confidence level upper limit of {sigma}{sub WW}xBR(W{yields}l{nu}{sub l},W{yields}jets)+{sigma}{sub…

PhysicsNuclear and High Energy PhysicsParticle physicsGauge bosonMuon010308 nuclear & particles physicsHadronHigh Energy Physics::PhenomenologyTevatronGeneral Physics and AstronomyElementary particleCoupling (probability)01 natural sciencesStandard ModelNuclear physicsMassless particleParticle decay0103 physical sciencesProduction (computer science)High Energy Physics::ExperimentSensitivity (control systems)010306 general physicsLeptonBosonPhysical Review Letters
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Search for Large Extra Dimensions in Final States Containing One Photon or Jet and Large Missing Transverse Energy Produced inpp¯Collisions ats=1.96 …

2008

We present the results of searches for large extra dimensions in samples of events with large missing transverse energy E_{T} and either a photon or a jet produced in pp[over ] collisions at sqrt[s]=1.96 TeV collected with the Collider Detector at Fermilab II. For gamma+E_{T} and jet+E_{T} candidate samples corresponding to 2.0 and 1.1 fb;{-1} of integrated luminosity, respectively, we observe good agreement with standard model expectations and obtain a combined lower limit on the fundamental parameter of the large extra dimensions model M_{D} as a function of the number of extra dimensions in the model.

PhysicsJet (fluid)Particle physicsPhotonLuminosity (scattering theory)010308 nuclear & particles physicsGeneral Physics and Astronomy7. Clean energy01 natural sciencesStandard ModelNuclear physicsExtra dimensions0103 physical sciencesLarge extra dimensionHigh Energy Physics::Experiment010306 general physicsCollider Detector at FermilabEnergy (signal processing)Physical Review Letters
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Search for diphoton events with large missing transverse energy in 7 TeV proton-proton collisions with the ATLAS detector.

2011

A search for diphoton events with large missing transverse energy is presented. The data were collected with the ATLAS detector in proton-proton collisions at √s=7  TeV at the CERN Large Hadron Collider and correspond to an integrated luminosity of 3.1  pb−1. No excess of such events is observed above the standard model background prediction. In the context of a specific model with one universal extra dimension with compactification radius R and gravity-induced decays, values of 1/R<729  GeV are excluded at 95% C. L., providing the most sensitive limit on this model to date.

Particle physicsMISSING TRANSVERSE ENERGYCiências Naturais::Ciências FísicasAtlas detector:Ciências Físicas [Ciências Naturais]FIS/04 - Fisica Nucleare e SubnucleareGeneral Physics and AstronomyFOS: Physical sciencestransverse energy: missing-energy ; ATLAS ; universal extra dimension ; compactification ; CERN LHC Coll ; background ; p p: interaction ; final state: two-photon ; photon: Kaluza-Klein ; electroweak interaction: standard model: validity test ; experimental results ; 7000 GeV-cmsddc:500.201 natural sciences7. Clean energy530High Energy Physics - ExperimentNuclear physicsUniversal extra dimensionHigh Energy Physics - Experiment (hep-ex)0103 physical sciencesddc:550[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]diphoton; events; transverse energy;proton-proton collisions; Hadron;ddc:530High Energy PhysicsSpecific model010306 general physicsNuclear ExperimentGeneralLiterature_REFERENCE(e.g.dictionariesencyclopediasglossaries)QCPhysicsLarge Hadron ColliderScience & TechnologyCompactification (physics)010308 nuclear & particles physicsAtlas (topology)Settore FIS/01 - Fisica SperimentaleFísicaFIS/01 - Fisica SperimentaleATLASTransverse planeCol·lisions (Física nuclear)Experimental High Energy PhysicsUniversal Extra DimensionsFísica nuclearHigh Energy Physics::ExperimentLHCParticle Physics - ExperimentPhysical review letters
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