Search
Results
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Study of inclusive strange-baryon production and search for pentaquarks in two-photon collisions at LEP
(2007)The European Physical Journal CMeasurements of inclusive production of the Λ, Ξ- and Ξ*(1530) baryons in two-photon collisions with the L3 detector at LEP are presented. The inclusive differential cross sections for Λ and Ξ- are measured as a function of the baryon transverse momentum, pt, and pseudo-rapidity, η. The mean number of Λ, Ξ- and Ξ*(1530) baryons per hadronic two-photon event is determined in the kinematic range 0.4 GeV<pt<2.5 GeV, |η|<1.2. Overall agreement ...Journal Article -
Search for neutral MSSM Higgs bosons at LEP
(2006)The European Physical Journal CThe four LEP collaborations, ALEPH, DELPHI, L3 and OPAL, have searched for the neutral Higgs bosons which are predicted by the Minimal Supersymmetric standard model (MSSM). The data of the four collaborations are statistically combined and examined for their consistency with the background hypothesis and with a possible Higgs boson signal. The combined LEP data show no significant excess of events which would indicate the production of ...Journal Article -
Reconstruction of the signal amplitude of the CMS electromagnetic calorimeter
(2006)The European Physical Journal CThe amplitude of the signal collected from the PbWO4 crystals of the CMS electromagnetic calorimeter is reconstructed by a digital filtering technique. The amplitude reconstruction has been studied with test beam data recorded from a fully equipped barrel supermodule. Issues specific to data taken in the test beam are investigated, and the implementation of the method for CMS data taking is discussed.Journal Article -
Measurement of hadron and lepton-pair production in e+e- collisions at root s=192-208 GeV at LEP
(2006)The European Physical Journal CHadron production and lepton-pair production in e+e- collisions are studied with data collected with the L3 detector at LEP at centre-of-mass energies s√=192−208GeV. Using a total integrated luminosity of 453 pb-1, 36057 hadronic events and 12863 lepton-pair events are selected. The cross sections for hadron production and lepton-pair production are measured for the full sample and for events where no high-energy initial-state-radiation ...Journal Article -
Measurement of the mass and the width of the W boson at LEP
(2006)The European Physical Journal CThe mass and the total decay width of the W boson are measured with the L3 detector at the LEP e+e– collider using W-boson pairs produced in 0.7 fb–1 of data collected at centre-of-mass energies between 161 and 209 GeV. Combining semi-leptonic and fully-hadronic final states, the mass and the width of the W boson are determined to be mW=80.270±0.046±0.031GeVandΓW=2.18±0.11±0.09GeV where the first uncertainty is statistical and the ...Journal Article -
Results of the first performance tests of the CMS electromagnetic calorimeter
(2006)The European Physical Journal CPerformance tests of some aspects of the CMS ECAL were carried out on modules of the "barrel" sub-system in 2002 and 2003. A brief test with high energy electron beams was made in late 2003 to validate prototypes of the new Very Front End electronics. The final versions of the monitoring and cooling systems, and of the high and low voltage regulation were used in these tests. The results are consistent with the performance targets including ...Journal Article -
Measurement of the running of the electromagnetic coupling at large momentum-transfer at LEP
(2005)Physics Letters BThe evolution of the electromagnetic coupling, α, in the momentum-transfer range 1800 GeV2 < -Q2 < 21600 GeV2 is studied with about 40 000 Bhabha-scattering events collected with the L3 detector at LEP at centre-of-mass energies √s = 189-209 GeV. The running of α is parametrised as: α(Q2) = α0/1 - C Δα(Q2), where α ≡ α(Q2 = 0) is the fine-structure constant and C = 1 corresponds to the evolution expected in QED. A fit to the differential ...Journal Article -
Neutral-current four-fermion production in e+e- interactions at LEP
(2005)Physics Letters BNeutral-current four-fermion production, e+e -→ff̄f′f̄′, is studied in 0.7 fb -1 of data collected with the L3 detector at LEP at centre-of-mass energies s=183-209 GeV. Four final states are considered: qq̄νν̄ , qq̄ℓ+ℓ-, ℓ+ℓ-ℓ′+ℓ′- and ℓ+ℓ-νν̄, where ℓ denotes either an electron or a muon. Their cross sections are measured and found to agree with the Standard Model predictions. In addition, the e+e-→Zγ *→ff̄f′f̄′ process is studied and ...Journal Article -
Summary of the CMS potential for the Higgs boson discovery
(2005)The European Physical Journal CThis work summarizes the studies for the Higgs boson searches in CMS at the LHC collider. The main discovery channels are presented and the potential is given for the discovery of the SM Higgs boson and the Higgs bosons of the MSSM. The phenomenology, detector, trigger and reconstruction issues are briefly discussed.Journal Article -
Measurement of the cross section of W-boson pair production at LEP
(2004)Physics Letters BThe cross section of W-boson pair-production is measured with the L3 detector at LEP. In a data sample corresponding to a total luminosity of 629.4 pb−1, collected at centre-of-mass energies ranging from 189 to 209 GeV, 9834 four-fermion events with W bosons decaying into hadrons or leptons are selected. The total cross section is measured with a precision of 1.4% and agrees with the Standard Model expectation. Assuming charged-lepton ...Journal Article