We have studied the reactions e +e -→hadrons, e +e -, μ + μ - and τ + τ -, in the energy range 88.2 {Mathematical expression} GeV. A total luminosity of 5.5 pb -1, corresponding to approximately 115000 hadronic and 10000 leptonic Z 0 decays, has been recorded with the L3 detector. From a simultaneous fit to all of our measured cross section data, we obtain assuming lepton universality: {Mathematical expression} If we do not assume lepton universality, we obtain for the partial decay widths of the Z 0 into e +e - μ + μ - and τ + τ -: {Mathematical expression} From the measured ratio of the invisible and the leptonic decay widths of the Z 0, we determine the number of light neutrino species to be N v=3.05±0.10. We include our measurements of the forward-backward asymmetry for the leptonic channels in a fit to determine the vector and axial-vector neutral current coupling constants of charged leptons to the Z 0. We obtain {Mathematical expression} and {Mathematical expression}. In the framework of the Standard Model, we estimate the top quark mass to be m t=193 -69 +52±16 (Higgs) GeV, and we derive a value for the weak mixing angle of sin 2θ W=1-(M W/M Z) 2=0.222 ± 0.008, corresponding to an effective weak mixing angle of {Mathematical expression}. © 1991 Springer-Verlag.

Measurement of electroweak parameters from hadronic and leptonic decays of the Z 0 / B., A., O., A., M., A.B., H., A., J., A., Aloisio, A., G., A., Alviggi, M., Q., A., H., A., A. L., A., V. P., A., T., A., L., A., D., A., P., A., A., A., T., A., T., A., P. V. K. S., B., et al.. - In: ZEITSCHRIFT FÜR PHYSIK. C, PARTICLES AND FIELDS. - ISSN 0170-9739. - STAMPA. - 51:(1991), pp. 179-203. [10.1007/BF01475788]

Measurement of electroweak parameters from hadronic and leptonic decays of the Z 0

ALOISIO, ALBERTO;ALVIGGI, MARIAGRAZIA;CHIEFARI, GIOVANNI;MEROLA, LEONARDO;NAPOLITANO, MARCO;PATERNOSTER, GIOVANNI;PATRICELLI, SERGIO;SCIACCA, CRISOSTOMO;
1991

Abstract

We have studied the reactions e +e -→hadrons, e +e -, μ + μ - and τ + τ -, in the energy range 88.2 {Mathematical expression} GeV. A total luminosity of 5.5 pb -1, corresponding to approximately 115000 hadronic and 10000 leptonic Z 0 decays, has been recorded with the L3 detector. From a simultaneous fit to all of our measured cross section data, we obtain assuming lepton universality: {Mathematical expression} If we do not assume lepton universality, we obtain for the partial decay widths of the Z 0 into e +e - μ + μ - and τ + τ -: {Mathematical expression} From the measured ratio of the invisible and the leptonic decay widths of the Z 0, we determine the number of light neutrino species to be N v=3.05±0.10. We include our measurements of the forward-backward asymmetry for the leptonic channels in a fit to determine the vector and axial-vector neutral current coupling constants of charged leptons to the Z 0. We obtain {Mathematical expression} and {Mathematical expression}. In the framework of the Standard Model, we estimate the top quark mass to be m t=193 -69 +52±16 (Higgs) GeV, and we derive a value for the weak mixing angle of sin 2θ W=1-(M W/M Z) 2=0.222 ± 0.008, corresponding to an effective weak mixing angle of {Mathematical expression}. © 1991 Springer-Verlag.
1991
Measurement of electroweak parameters from hadronic and leptonic decays of the Z 0 / B., A., O., A., M., A.B., H., A., J., A., Aloisio, A., G., A., Alviggi, M., Q., A., H., A., A. L., A., V. P., A., T., A., L., A., D., A., P., A., A., A., T., A., T., A., P. V. K. S., B., et al.. - In: ZEITSCHRIFT FÜR PHYSIK. C, PARTICLES AND FIELDS. - ISSN 0170-9739. - STAMPA. - 51:(1991), pp. 179-203. [10.1007/BF01475788]
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11588/465342
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