Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
}
TY - JOUR
T1 - Update of electroweak parameters fromZ decays
AU - Buskulic, D.
AU - Finch, Alexander
AU - ALEPH Collaboration
PY - 1993
Y1 - 1993
N2 - Based on 520 000 fermion pairs accumulated during the first three years of data collection by the ALEPH detector at LEP, updated values of the resonance parameters of theZ are determined to beMZ=(91.187±0.009) GeV, ΓZ=(2.501±0.012) GeV, σhad0=(41.60±0.27) nb, andRℓ=20.78±0.13. The corresponding number of light neutrino species isNν=2.97±0.05. The forward-backward asymmetry in lepton-pair decays is used to determine the ratio of vector to axial-vector couplings of leptons:gV2(MZ2)/gA2(MZ2)=0.0052±0.0016. Combining this with ALEPH measurements of theb andc quark asymmetries and τ polarization gives sin2θWeff=0.2326±0.0013. Assuming the minimal Standard Model, and including measurements ofMW/MZ frompp ¯ colliders and neutrino-nucleon scattering, the mass of the top quark isM top =156±22 25 ±17 22Higgs GeV.
AB - Based on 520 000 fermion pairs accumulated during the first three years of data collection by the ALEPH detector at LEP, updated values of the resonance parameters of theZ are determined to beMZ=(91.187±0.009) GeV, ΓZ=(2.501±0.012) GeV, σhad0=(41.60±0.27) nb, andRℓ=20.78±0.13. The corresponding number of light neutrino species isNν=2.97±0.05. The forward-backward asymmetry in lepton-pair decays is used to determine the ratio of vector to axial-vector couplings of leptons:gV2(MZ2)/gA2(MZ2)=0.0052±0.0016. Combining this with ALEPH measurements of theb andc quark asymmetries and τ polarization gives sin2θWeff=0.2326±0.0013. Assuming the minimal Standard Model, and including measurements ofMW/MZ frompp ¯ colliders and neutrino-nucleon scattering, the mass of the top quark isM top =156±22 25 ±17 22Higgs GeV.
U2 - 10.1007/BF01650432
DO - 10.1007/BF01650432
M3 - Journal article
VL - 60
SP - 71
EP - 81
JO - Zeitschrift für Physik C Particles and Fields
JF - Zeitschrift für Physik C Particles and Fields
SN - 0170-9739
IS - 1
ER -