arXiv subjects

L3 collaboration

Publications and source records attributed to L3 collaboration.

3 recordsLinked to original sources

arXiv2003

Proton-Antiproton Pair Production in Two-Photon Collisions at LEP

The reaction e^+e^- -> e^+e^- proton antiproton is studied with the L3 detector at LEP. The analysis is based on data collected at e^+e^- center-of-mass energies from 183 GeV to 209 GeV, corresponding to an integrated luminosity of 667 pb^-1. The gamma gamma -> proton antiproton differential cross section is measured in the range of the two-photon center-of-mass energy from 2.1 GeV to 4.5 GeV. The results are compared to the predictions of the three-quark and quark-diquark models.

hep-ex↗

arXiv2002

The e+e- -> Z gamma gamma -> q q gamma gamma Reaction at LEP and Constraints on Anomalous Quartic Gauge Boson Couplings

The cross section of the process e^+ e^- -> Z γγ-> qq γγis measured with 215 pb^-1 of data collected with the L3 detector during the final LEP run at centre-of-mass energies around 205 GeV and 207 GeV. No deviation from the Standard Model expectation is observed. The full data sample of 713 pb^-1, collected above the Z resonance, is used to constrain the coefficients of anomalous quartic gauge boson couplings to: -0.02 GeV^-2 < a_0/Λ^2 < 0.03 GeV^-2 and -0.07 GeV^-2 < a_c/Λ^2 < 0.05 GeV^-2, at 95% confidence level.

hep-ex↗

arXiv2001

A Combination of Preliminary Electroweak Measurements and Constraints on the Standard Model

This note presents a combination of published and preliminary electroweak results from the four LEP collaborations and the SLD collaboration which were prepared for the 2000 summer conferences. Averages from Z0 resonance results are derived for hadronic and leptonic cross sections, the leptonic forward-backward asymmetries, the tau polarisation asymmetries, the bbbar and ccbar partial widths and forward-backward asymmetries and the qqbar charge asymmetry. Above the Z0 resonance, averages are derived for di-fermion cross sections and asymmetries, W-pair, Z-pair and single-W production cross section, electroweak gauge boson couplings and W mass and decay branching ratios. The major changes with respect to results presented in summer 1999 are final Z0 lineshape results from LEP, updates to the W mass and gauge-boson couplings from LEP, and ALR from SLD. The results are compared with precise electroweak measurements from other experiments. The parameters of the Standard Model are evaluated, first using the combined LEP electroweak measurements, and then using the full set of electroweak results.

hep-ex↗