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Search for colour reconnection effects in e+e- -> W+W- -> hadrons through particle-flow studies at LEP
(2003)Physics Letters BA search for colour reconnection effects in hadronic decays of W pairs is performed with the L3 detector at centre-of-mass energies between 189 and 209 GeV. The analysis is based on the study of the particle flow between jets associated to the sameW boson and between two different W bosons in qqqq events. The ratio of particle yields in the different interjet regions is found to be sensitive to colour reconnection effects implemented in ...Journal Article -
Z boson pair-production at LEP
(2003)Physics Letters BEvents stemming from the pair-production of Z bosons in e+e- collisions are studied using 217.4 pb-1 of data collected with the L3 detector at centre-of-mass energies from 200 GeV up to 209 GeV. The special case of events with b quarks is also investigated. Combining these events with those collected at lower centre-of-mass energies, the Standard Model predictions for the production mechanism are verified. In addition, limits are set on ...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 -
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