0000000001061297

AUTHOR

J. Cowell

showing 3 related works from this author

Search for composite and exotic fermions at LEP 2

1999

A search for unstable heavy fermions with the DELPHI detector at LEP is reported. Sequential and non-canonical leptons, as well as excited leptons and quarks, are considered. The data analysed correspond to an integrated luminosity of about 48~pb$^{-1}$ at an $e^+e^-$ centre-of-mass energy of 183~GeV and about 20~pb$^{-1}$ equally shared between the centre-of-mass energies of 172~GeV and 161~GeV. The search for pair-produced new leptons establishes 95\% confidence level mass limits in the region between 70~GeV/$c^2$ and 90~GeV/$c^2$, depending on the channel. The search for singly produced excited leptons and quarks establishes upper limits on the ratio of the coupling of the excited fermio…

QuarkParticle physicsPhysics and Astronomy (miscellaneous)PAIR PRODUCTIONCHARGED HEAVY-LEPTONSFOS: Physical sciences7. Clean energy01 natural sciencesPartícules (Física nuclear)CROSS-SECTIONSHigh Energy Physics - ExperimentE(+)E(-) COLLISIONSBHABHA SCATTERINGHigh Energy Physics - Experiment (hep-ex)0103 physical sciencesMONTE-CARLO PROGRAM[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]RADIATIVE-CORRECTIONS010306 general physicsNuclear ExperimentEngineering (miscellaneous)PhysicsLuminosity (scattering theory)010308 nuclear & particles physicsHigh Energy Physics::PhenomenologyFermionCoupling (probability)Z0 DECAYSExcited stateHigh Energy Physics::ExperimentFísica nuclearROOT-S=161 GEVEXCITED LEPTONSCHARGED HEAVY-LEPTONS; MONTE-CARLO PROGRAM; EXCITED LEPTONS; E(+)E(-) COLLISIONS; Z0 DECAYS; ROOT-S=161 GEV; RADIATIVE-CORRECTIONS; BHABHA SCATTERING; PAIR PRODUCTION; CROSS-SECTIONSParticle Physics - ExperimentLepton
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A search for $\eta'_c$ production in photon-photon fusion at LEP

1998

A search for the production of the $\eta'_c$ meson, the first radial excitation of the ground state of charmonium $\eta_c$(2980), in the photon-photon fusion reaction at LEP has been performed using the data collected by the DELPHI detector during 1992-1996. No evidence of $\eta'_c$ production is found in the mass region 3520--3800 MeV/c^2. An upper limit for the ratio of the two-photon widths of the $\eta'_c$ and $\eta_c$ is obtained.

Nuclear and High Energy PhysicsParticle physicsPhotonMesonHigh Energy Physics::LatticeWidth ratio01 natural sciencesPartícules (Física nuclear)High Energy Physics - ExperimentNuclear physics0103 physical sciences[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]Nuclear fusion010306 general physicsNuclear ExperimentDELPHIPhysicsFusion010308 nuclear & particles physicsHigh Energy Physics::PhenomenologyLARGE ELECTRON POSITRON COLLIDERLarge Electron–Positron ColliderPARTICLE PHYSICS; LARGE ELECTRON POSITRON COLLIDER; DELPHIPARTICLE PHYSICSFísica nuclearHigh Energy Physics::ExperimentGround stateExcitationParticle Physics - Experiment
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Measurement of the mass of the W boson using direct reconstruction at √s = 183 GeV

1999

From data corresponding to an integrated luminosity of 53.5 pb(-1) taken during the 183 GeV run in 1997, DELPHI has measured the W mass from direct reconstruction of WW --> lq (q) over bar and WW --> q (q) over bar q (q) over bar events. Combining these channels, a value of m(w) = 80.238 +/- 0.154(stat) +/- 0.035(syst) +/- 0.035(fsi) +/- 0.021 (LEP) GeV/c(2) is obtained, where fsi denotes final state interaction. Combined with the W mass obtained by DELPHI from the WW production cross-section and with the direct measurement at 172 GeV this leads to a measured value of m(w) = 80.270 +/- 0.137(stat) +/- 0.031(syst) +/- 0.030(fsi) +/- 0.021(LEP)GeV/c(2), in good agreement with the Standard Mod…

Nuclear and High Energy PhysicsParticle physicsEINSTEIN CORRELATIONSCLUSTERING-ALGORITHMElectron–positron annihilationMathematicsofComputing_GENERALCOLOR DIPOLE MODEL01 natural sciencesComputer Science::Digital LibrariesPartícules (Física nuclear)LuminosityStandard ModelPHYSICSEVENTSNuclear physicsLEP20103 physical sciencesMONTE-CARLO PROGRAM[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]ANNIHILATION010306 general physicsDELPHIPhysicsAnnihilation010308 nuclear & particles physicsE(+)E(-) INTERACTIONSTheoryofComputation_GENERALLARGE ELECTRON POSITRON COLLIDERMONTE-CARLO PROGRAM; PAIR CROSS-SECTION; COLOR DIPOLE MODEL; E(+)E(-) INTERACTIONS; EINSTEIN CORRELATIONS; CLUSTERING-ALGORITHM; ANNIHILATION; PHYSICS; EVENTS; LEP2PARTICLE PHYSICS; LARGE ELECTRON POSITRON COLLIDER; DELPHIComputer Science::Mathematical SoftwarePARTICLE PHYSICSProduction (computer science)Física nuclearPAIR CROSS-SECTIONParticle Physics - ExperimentBar (unit)
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