Precision measurement of the W-boson properties with the L3 detector at LEP
Abstract
W-boson properties, such as W-boson pair production cross-section, W-boson mass, total decay width and triple gauge-boson couplings (TGC) are measured with the L3 detector at LEP. The data sample used in the analyses correspond to a total luminosity of 629.4 pb-1, collected at center-of-mass energies ranging from 189 GeV to 209 GeV. 9834 four-fermion events with W-boson decaying into either hadrons or leptons are selected. Single channel cross-sections are derived with no assumption on W-boson branching fractions. The total cross-section is measured with a precision of 1.4% and agrees with the Standard Model expectation. The W-boson mass, MW, and total decay width, GW , have been measured using directly reconstructed semi leptonic and hadronic events. Combining all final states in W-boson pair production, MW and GW are measured to be MW=80.252+/-0.045 stat+/-0.038 systGeV GW=2.429+/-0.128 stat+/-0.129syst GeV These results are preliminary. The CP-conserving triple gauge-boson couplings, gZ1,kg ,lg are measured in hadronic and semi-leptonic W-boson pair events. The results are in good agreement with Standard Model expectations and are found to be gZ1=0.966+/-0.034 stat+/-0.015 syst, kg=0.910+/-0.074 stat+/-0.039 syst, lg=-0.024+/-0.035 stat+/-0.017 syst.
- Publication:
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Ph.D. Thesis
- Pub Date:
- 2004
- Bibcode:
- 2004PhDT.......167P