0000000001194043

AUTHOR

J. Perkins

showing 7 related works from this author

Ratio of Isolated Photon Cross Sections in pp¯ Collisions at √s=630 and 1800 GeV

2001

The inclusive cross section for production of isolated photons has been measured in p (p) over bar collisions at roots = 630 GeV with the DO detector at the Fermilab Tevatron Collider. The photons span a transverse energy (E-T) range from 7-49 GeV and have pseudorapidity \eta\ s = 1800 GeV to form a ratio of the cross sections. Comparison of next-to-leading-order QCD with the measured cross section at 630 GeV and the ratio of cross sections show satisfactory agreement in most of the E-T range.

PhysicsQuantum chromodynamicsParticle physicsPhoton010308 nuclear & particles physicsTevatronGeneral Physics and Astronomy7. Clean energy01 natural scienceslaw.inventionNuclear physicsCross section (physics)lawPseudorapidity0103 physical sciencesHigh Energy Physics::ExperimentFermilabNuclear Experiment010306 general physicsColliderBar (unit)Physical Review Letters
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Search for Leptoquark Pairs Decaying intoνν+jetsinpp¯Collisions ats=1.8TeV

2002

We present the results of a search for leptoquark (LQ) pairs in (85.2+/-3.7) pb(-1) of pp* collider data collected by the D0 experiment at the Fermilab Tevatron. We observe no evidence for leptoquark production and set a limit on sigma(pp*-->LQLQ-->nunu+jets) as a function of the mass of the leptoquark (m(LQ)). Assuming the decay LQ-->nuq, we exclude scalar leptoquarks for m(LQ) < 98 GeV/c(2), and vector leptoquarks for m(LQ) < 200 GeV/c(2) and coupling which produces the minimum cross section, at a 95% confidence level.

PhysicsParticle physics010308 nuclear & particles physicsHigh Energy Physics::PhenomenologyScalar (mathematics)TevatronGeneral Physics and AstronomySigmaD0 experiment7. Clean energy01 natural scienceslaw.inventionNuclear physicslaw0103 physical sciencesHigh Energy Physics::ExperimentLeptoquarkFermilab010306 general physicsColliderPhysical Review Letters
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Search for the Scalar Top Quark inpp¯Collisions ats=1.8TeV

2002

We have performed a search for scalar top quark (stop) pair production in the inclusive electron-muon-missing transverse energy final state, using a sample of p (p) over bar events corresponding to 108.3 pb (-1) of data collected with the D0 detector at Fermilab. The search is done in the framework of the minimal supersymmetric standard model assuming that the sneutrino is the lightest supersymmetric particle. For the dominant decays of the lightest stop, (t) over tilde-->b (χ) over tilde (+)(1) and (t) over tilde-->bl (ν) over tilde , no evidence for signal is found. We derive cross-section limits as a function of stop ((t) over tilde), chargino ((χ) over tilde (+)(1)), and sneutrino ((ν) …

PhysicsParticle physicsTop quark010308 nuclear & particles physicsHigh Energy Physics::PhenomenologyScalar (mathematics)General Physics and AstronomySupersymmetry01 natural sciencesLightest Supersymmetric ParticleNuclear physicsCharginoPair production0103 physical sciencesHigh Energy Physics::ExperimentFermilab010306 general physicsMinimal Supersymmetric Standard ModelPhysical Review Letters
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Search for R-parity violating supersymmetry in two-muon and four-jet topologies

2002

We present results of a search for R-parity-violating decay of the neutralino chi;01, taken as the lightest supersymmetric particle, to a muon and two jets. The decay proceeds through a lepton-number violating coupling lambda(')(2jk) (j=1,2; k=1,2,3), with R-parity conservation in all other production and decay processes. In the absence of candidate events from 77.5+/-3.9 pb(-1) of data collected by the D0 experiment at the Fermilab Tevatron in pp collisions at sqrt[s]=1.8 TeV, and with an expected background of 0.18+/-0.03+/-0.02 events, we set limits on squark and gluino masses within the framework of the minimal low-energy supergravity-supersymmetry model.

PhysicsParticle physicsMuon010308 nuclear & particles physicsHigh Energy Physics::PhenomenologyTevatronGeneral Physics and AstronomySupersymmetryD0 experiment7. Clean energy01 natural sciencesLightest Supersymmetric ParticleNuclear physicsR-parityExperimental High Energy Physics0103 physical sciencesNeutralino[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]High Energy Physics::ExperimentFermilab010306 general physics
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Subjet multiplicity of gluon and quark jets reconstructed with thek⊥algorithm inpp¯collisions

2002

The D empty set Collaboration has studied for the first time the properties of hadron-collider jets reconstructed with a successive-combination algorithm based on relative transverse momenta (k(perpendicular to)) of energy clusters. Using the standard value D = 1.0 of the jet-separation parameter in the k(perpendicular to) algorithm, we find that the p(T) of such jets is higher than the E-T of matched jets reconstructed with cones of radius R = 0.7, by about 5 (8) GeV at p(T) approximate to90 (240) GeV. To examine internal jet structure, the k(perpendicular to) algorithm is applied within D = 0.5 jets to resolve any subjets. The multiplicity of subjets in jet samples at roots = 1800 GeV and…

QuarkPhysicsNuclear and High Energy PhysicsParticle physics010308 nuclear & particles physicsAstrophysics::High Energy Astrophysical PhenomenaMultiplicity (mathematics)RadiusJet (particle physics)Deep inelastic scattering01 natural sciencesGluonNuclear physics0103 physical sciencesHigh Energy Physics::ExperimentResummationNuclear Experiment010306 general physicsAlgorithmEvent generatorPhysical Review D
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Search for Heavy Particles Decaying into Electron-Positron Pairs inpp¯Collisions

2001

We present results of searches for technirho (rho (T)), techniomega (omega (T)), and Z' particles, using the decay channels rho (T), omega (T), Z' --> e(+)e(-). The search is based on 124.8 pb(-1) of data collected by the DO detector at the Fermilab Tevatron during 1992-1996. In the absence of a signal, we set 95% C.L. upper limits on the cross sections for the processes p (p) over bar --> rho (T), omega (T), Z' - e(+)e(-) as a function of the mass of the decaying particle. For certain model parameters, we exclude the existence of degenerate rho (T) and omega (T) states with masses below about 200 GeV. We exclude a Z' with mass below 670 GeV, assuming that it has the same couplings to fermi…

PhysicsParticle physicsGauge boson010308 nuclear & particles physicsTevatronGeneral Physics and AstronomyTechnicolorElectronFermion01 natural sciences7. Clean energyOmegaNuclear physicsPositron0103 physical sciencesHigh Energy Physics::ExperimentFermilab010306 general physicsPhysical Review Letters
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Erratum to “Choices of Stent and Cerebral Protection in the Ongoing ACST-2 Trial: A Descriptive Study” (European Journal of Vascular and Endovascular…

2017

Due to a miscommunication during the production of this article, the members of the ACST-2 Collaborative Group were not properly indexed in PubMed. This has now been corrected online. We apologize for any confusion or inconvenience that this oversight might have caused.

Surgery; Cardiology and Cardiovascular MedicineSurgeryCardiology and Cardiovascular MedicineSettore MED/22 - Chirurgia Vascolare
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