The properties of the Z resonance are measured on the basis of 190000 Z decays into fermion pairs collected with the ALEPH detector at LEP. Assuming lepton universality, M(Z) = (91.182 +/- 0.009(exp.) +/- 0.020 (Z->b bbar)) GeV, GAMMA(Z) = (2484 +/- 17) MeV, sigma(had)0 = (41.44 +/- 0.36) nb, and GAMMA(had)/GAMMA(ll) = 21.00 +/- 0.20. The corresponding number of light neutrino species is 2.97 +/- 0.07. The forward-backward asymmetry in leptonic decays is used to determine the ratio of vector to axial-vector coupling constants of leptons: g(V)2(M(Z)2)/g(A)2(M(Z)2) = 0.0072 +/- 0.0027. Combining these results with ALEPH results on quark charge and b bbar asymmetries, and tau-polarization, sin^2( theta(W)(M^2(Z))) = 0.2312 +/- 0.0018. In the context of the Minimal Standard Model, limits are placed on the top-quark mass.

D., D., B., D., C., G., J. P., L., M. N., M., R., A., et al. (1992). Improved Measurements of Electroweak Parameters From Z-decays Into Fermion Pairs. ZEITSCHRIFT FÜR PHYSIK. C, PARTICLES AND FIELDS, 53(1), 1-20 [10.1007/BF01483868].

Improved Measurements of Electroweak Parameters From Z-decays Into Fermion Pairs

BOTTIGLI, UBALDO;CIOCCI, MARIA AGNESE;MARROCCHESI, PIER SIMONE;
1992-01-01

Abstract

The properties of the Z resonance are measured on the basis of 190000 Z decays into fermion pairs collected with the ALEPH detector at LEP. Assuming lepton universality, M(Z) = (91.182 +/- 0.009(exp.) +/- 0.020 (Z->b bbar)) GeV, GAMMA(Z) = (2484 +/- 17) MeV, sigma(had)0 = (41.44 +/- 0.36) nb, and GAMMA(had)/GAMMA(ll) = 21.00 +/- 0.20. The corresponding number of light neutrino species is 2.97 +/- 0.07. The forward-backward asymmetry in leptonic decays is used to determine the ratio of vector to axial-vector coupling constants of leptons: g(V)2(M(Z)2)/g(A)2(M(Z)2) = 0.0072 +/- 0.0027. Combining these results with ALEPH results on quark charge and b bbar asymmetries, and tau-polarization, sin^2( theta(W)(M^2(Z))) = 0.2312 +/- 0.0018. In the context of the Minimal Standard Model, limits are placed on the top-quark mass.
1992
D., D., B., D., C., G., J. P., L., M. N., M., R., A., et al. (1992). Improved Measurements of Electroweak Parameters From Z-decays Into Fermion Pairs. ZEITSCHRIFT FÜR PHYSIK. C, PARTICLES AND FIELDS, 53(1), 1-20 [10.1007/BF01483868].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11365/37579
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