Search
Results
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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 -
Single- and multi-photon events with missing energy in e+e- collisions at LEP
(2004)Physics Letters BSingle- and multi-photon events with missing energy are selected in 619 pb−1 of data collected by the L3 detector at LEP at centre-of-mass energies between 189 and 209 GeV. The cross sections of the process e+e−→ν ̄νγ (γ ) are found to be in agreement with the Standard Model expectations, and the number of light neutrino species is determined, including lower energy data, to be Nν=2.98±0.05±0.04. Selection results are given in the form ...Journal Article -
The CMS barrel calorimeter response to particle beams from 2 to 350 GeV/c
(2009)The European Physical Journal CThe response of the CMS barrel calorimeter (electromagnetic plus hadronic) to hadrons, electrons and muons over a wide momentum range from 2 to 350 GeV/c has been measured. To our knowledge, this is the widest range of momenta in which any calorimeter system has been studied. These tests, carried out at the H2 beam-line at CERN, provide a wealth of information, especially at low energies. The analysis of the differences in calorimeter ...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 -
Measurement of W polarisation at LEP
(2003)Physics Letters BThe three different helicity states of W bosons produced in the reaction e+e- →W+W-→lνqq-' at LEP are studied using leptonic and hadronic W decays. Data at centre-of-mass energies √s = 183-209 GeV are used to measure the polarisation of Wbosons, and its dependence on theWboson production angle. The fraction of longitudinally polarisedWbosons is measured to be 0.218 ± 0.027 ± 0.016 where the first uncertainty is statistical and the second ...Journal Article -
Study of the e+e- -> Ze+e- process at LEP
(2003)Physics Letters BThe cross section of the process e+e- → Ze+e- is measured with 0.7 fb-1 of data collected with the L3 detector at LEP. Decays of the Z boson into quarks and muons are considered at centre-of-mass energies ranging from 183 GeV up to 209 GeV. The measurements are found to agree with Standard Model predictions, achieving a precision of about 10% for the hadronic channel.Journal Article -
Measurement of charged-particle multiplicity distributions and their H-q moments in hadronic Z decays at LEP
(2003)Physics Letters BThe charged-particle multiplicity distribution is measured for all hadronic events as well as for light-quark and b-quark events produced in e +e- collisions at the Z pole. Moments of the charged-particle multiplicity distributions are calculated. The Hq moments of the multiplicity distributions are studied, and their quasi-oscillations as a function of the rank of the moment are investigatedJournal Article -
Inclusive charged hadron production in two-photon collisions at LEP
(2003)Physics Letters BInclusive charged hadron production, e+e- →e+e-h±X, is studied using 414 pb-1 of data collected at LEP with the L3 detector at centre-of-mass energies between 189 and 202 GeV. Single particle inclusive differential cross sections are measured as a function of the particle transverse momentum, pt , and pseudo-rapidity, η. For pt≤ 1.5 GeV, the data are well described by an exponential, typical of soft hadronic processes. For higher pt , the ...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 -
Search for charged Higgs bosons at LEP
(2003)Physics Letters BA search for pair-produced charged Higgs bosons is performed with the L3 detector at LEP using data collected at centre-of-mass energies between 189 and 209 GeV, corresponding to an integrated luminosity of 629.4 pb-1. Decays into a charm and a strange quark or into a tau lepton and its neutrino are considered. No significant excess is observed and lower limits on the mass of the charged Higgs boson are derived at the 95% confidence level. ...Journal Article