Demierre, Ph.
L3
GA
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A Determination of electroweak parameters from Z0 decays into charged leptons

The L3 collaboration Adeva, B. ; Adriani, O. ; Aguilar-Benitez, M. ; et al.
Phys.Lett.B 250 (1990) 183-192, 1990.
Inspire Record 299253 DOI 10.17182/hepdata.29552

We have measured the partial widths for the three reactions e + e − → Z 0 → e + e − , μ + μ − , τ + τ − . The results are Γ ee = 84.3±1.3 MeV, √ Γ ee Γ μμ =83.9±1.4 MeV, and √ Γ ee Γ ττ =83.9±1.4 MeV, where the errors are statistical. The systematic errors are estimated to be 1.0 MeV, 0.9 MeV, and 1.4 MeV, respectively. We perform a simultaneous fit to the cross sections for the e + e − →e + e − , μ + μ − , and τ + τ − data, the differential cross section as a function of polar angle for the electron data, and the forward- backward asymmetry for the muon data. We obtain the leptonic partial with Γ ℓℓ =84.0±0.9 (stat.) MeV. The systematic error is estimated to be 0.8 MeV. Also, we obtain the axial-vector and vector weak coupling constants of charged leptons, g A =−0.500±0.003 and g ν =−0.064 −0.013 +0.017 .

5 data tables
Table 1

Cross section from 1990 data.

Table 2

Visible cross section obtained using the cuts required by Method I (see text of paper). (1989 and 1990 data).

Table 3

Visible cross section obtained using the cuts required by Method II (see text of paper). (1989 and 1990 data). RE = E+ E- --> E+ E- (GAMMA).

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A Determination of electroweak parameters from Z0 ---> mu+ mu- (gamma)

The L3 collaboration Adeva, B. ; Adriani, O. ; Aguilar-Benitez, M. ; et al.
Phys.Lett.B 247 (1990) 473-480, 1990.
Inspire Record 297172 DOI 10.17182/hepdata.29622

We have measured the partial width and forward-backward charge asymmetry for the reaction e + e - →Z 0 →μ + μ - (γ). We obtain a partial width Γ μμ of 83.3±1.3(stat)±0.9(sys) MeV and the following values for the vector and axial vector couplings: g v =−0.062 −0.015 +0.020 and g A =−0.497 −0.005 +0.005 . From our measurement of the partial width and the mass of the Z 0 boson we determine the effective electroweak mixing angle, sin 2 θ w =0.232±0.005, and the neutral current coupling strength parameter, ϱ =0.998±0.016.

4 data tables
Table 1

No description provided.

Table 2

Forward backward charge asymmetry.

Table 3

No description provided.

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Measurement of $g$(a) and $g(V$), the Neutral Current Coupling Constants to Leptons

The L3 collaboration Adeva, B. ; Adriani, O. ; Aguilar-Benitez, M. ; et al.
Phys.Lett.B 236 (1990) 109-115, 1990.
Inspire Record 283470 DOI 10.17182/hepdata.29715

We have measured both the rates and the forward-backward asymmetry of ℓ + ℓ − from Z 0 →ℓ + ℓ − (where ℓ= μ , τ ) with the L3 detector. We obtained Γ ℓℓ =88±4±3 MeV and the vector neutral current coupling constant, g v =0.00±0.07 and the axial vector neutral current coupling constant, g A =−0.515±0.015.

2 data tables
Table 1

No description provided.

Table 2

No description provided.